The Development of the Regenerable Catalytic System in Selective Catalytic Oxidation of Ammonia with High N2 Selectivity

Supported particulate noble-metal catalysts are widely used in industrial catalytic reactions. However, these metal species, whether in the form of nanoparticles or highly dispersed entities, tend to aggregate during reactions, leading to a reduced activity or selectivity. Addressing the frequent necessity for the replacement of industrial catalysts remains a significant challenge. Herein, we demonstrate the feasibility of the 'regenerable catalytic system' exemplified by selective catalytic oxidation of ammonia (NH3-SCO) employing Ag/Al2O3 catalysts. Results demonstrate that our highly dispersed Ag catalyst (Ag HD) maintains >90% N2 selectivity at 80% NH3 conversion and >80% N2 selectivity at 100% NH3 conversion after enduring 5 cycles of reducible aggregation and oxidative dispersion. Moreover, it consistently upholds over 98% N2 selectivity at 100% NH3 conversion after 10 cycles of Ar treatment. During the aggregation-dispersion process, the Ag HD catalyst intentionally aggregated into Ag nanoparticles (Ag NP) after H2 reduction and exhibited remarkable regenerable capabilities, returning to the Ag HD state after calcination in the air. This structural evolution was characterized through in situ transmission electron microscopy, atomically resolved high-angle annular dark-field scanning transmission electron microscopy, and X-ray absorption spectroscopy, revealing the on-site oxidative dispersion of Ag NP. Additionally, in situ diffuse reflectance infrared Fourier transform spectroscopy provided insights into the exceptional N2 selectivity on Ag HD catalysts, elucidating the critical role of NO+ intermediates. Our findings suggest a sustainable and cost-effective solution for various industry applications.

Decoration of Gold and Platinum Nanoparticle Catalysts by 1 nm Thick Metal Oxide Overlayer and Its Effect on the CO Oxidation Activity

Exfoliated M-Al layered double hydroxide (M-Al LDH; M = Mg, Co, Ni, and Zn) nanosheets were adsorbed on Au/SiO2 and calcined to transform LDH into mixed metal oxides (MMOs) and yield Au/SiO2 coated with a thin MMO overlayer. These catalysts showed a higher catalytic activity than pristine Au/SiO2. In particular, the 50% CO conversion temperature decreased by more than 250 °C for Co-Al MMO-coated Au/SiO2. In contrast, the deposition of CoAlOx on Au/SiO2 by impregnation or the deposition of Au on Co-Al MMO-coated SiO2 resulted in a worse catalytic activity. Moreover, the presence of a thick MMO overlayer decreased the catalytic activity, suggesting that the control of the overlayer thickness to less than 1 nm is a requisite for obtaining a high catalytic activity. Moreover, the thin Co-Al MMO overlayer on Au/SiO2 possessed abundant oxygen vacancies, which would play an important role in O2 activation, resulting in a highly active interface between Au and the defect-rich MMO on the Au NP surface. Finally, this can be applied to Pt/SiO2, and the obtained Co-Al MMO-coated Pt/SiO2 also exhibited a much improved catalytic activity for CO oxidation.

High Selectivity Cofactor NADH Regeneration Organic Iridium Complexes Used for High-Efficiency Chem-Enzyme Cascade Catalytic Hydrogen Transfer

Our research demonstrated that novel pentamethylcyclopentadienyl (Cp*) iridium pyridine sulfonamide complex PySO2NPh-Ir (7) could highly specifically catalyze nicotinamide adenine dinucleotide (NAD+) into the corresponding reducing cofactor NADH in cell growth media containing various biomolecules. The structures and catalytic mechanism of 7 were studied by single-crystal X-ray, NMR, electrochemical, and kinetic methods, and the formation of iridium hydride species Ir-H was confirmed to be the plausible hydride-transfer intermediate of 7. Moreover, benefiting from its high hydrogen-transfer activity and selectivity for NADH regeneration, 7 was used as an optimal metal catalyst to establish a chem-enzyme cascade catalytic hydrogen-transfer system, which realized the high-efficiency preparation of l-glutamic acid by combining with l-glutamate dehydrogenase (GLDH).

Low-Temperature Hydrogenation of CO2 to Methanol in Water on ZnO-Supported CuAu Nanoalloys

Optimizing processes and materials for the valorization of CO2 to hydrogen carriers or platform chemicals is a key step for mitigating global warming and for the sustainable use of renewables. We report here on the hydrogenation of CO2 in water on ZnO-supported CuAu nanoalloys, based on ≤7 mol % Au. Cux Auy /ZnO catalysts were characterized using 197 Au Mössbauer, in situ X-ray absorption (Au LIII - and Cu K-edges), and ambient pressure X-ray photoelectron (APXP) spectroscopic methods together with X-ray diffraction and high-resolution electron microscopy. At 200 °C, the conversion of CO2 showed a significant increase by 34 times (from 0.1 to 3.4 %) upon increasing Cu93 Au7 loading from 1 to 10 wt %, while maintaining methanol selectivity at 100 %. Limited CO selectivity (4-6 %) was observed upon increasing temperature up to 240 °C but associated with a ≈3-fold increase in CO2 conversion. Based on APXPS during CO2 hydrogenation in an H2 O-rich mixture, Cu segregates preferentially to the surface in a mainly metallic state, while slightly charged Au submerges deeper into the subsurface region. These results and detailed structural analyses are topics of the present contribution.

Metal-Support Interaction in Gold Zeolitic Octahedral Metal Oxide and the Catalytic Activity for Low-Temperature Alcohol Oxidation

Au nanoparticles are efficient catalysts for selective oxidations. The interaction between Au nanoparticles and supports is critical for achieving high catalytic activity. Herein, Au nanoparticles are supported on a zeolitic octahedral metal oxide based on Mo and V. The charge of Au is controlled by the surface oxygen vacancies of the supports, and the redox property of the zeolitic vanadomolybdate is highly dependent on Au loading. The Au-supported zeolitic vanadomolybdate is used as a heterogeneous catalyst for alcohol oxidation under mild conditions with molecular oxygen as an oxidant. The supported Au catalyst can be recovered and reused without the loss of activity.

Gold/Substituted Hydroxyapatites for Oxidative Esterification: Control of Thin Apatite Layer on Gold Based on Strong Metal-Support Interaction (SMSI) Results in High Activity

Gold nanoparticles (Au NPs) deposited on various cation- and anion-substituted hydroxyapatites (Au/sHAPs) show oxidative strong metal-support interaction (SMSI), wherein a thin layer of the sHAP covered the surface of the Au NPs by heat treatment in an oxidative atmosphere. Calcination of Au/sHAPs at 300 °C caused a partial SMSI and that at 500 °C gave fully encapsulated Au NPs. We investigated the influence of the substituted ions in sHAP and the degree of the oxidative SMSI on the catalytic performance of Au/sHAPs for oxidative esterification of octanal or 1-octanol with ethanol to obtain ethyl octanoate. The catalytic activity depends on the size of the Au NPs but not on the support used, owing to the similarity of the acid and base properties of sHAPs except for Au/CaFAP. The presence of a large number of acidic sites on CaFAP lowered the product selectivity, but all other sHAPs exhibited similar activity when the Au particle size was almost the same, owing to the similarity of the acid and base properties. Au/sHAPs_O₂ with SMSI exhibited higher catalytic activity than Au/sHAPs_H₂ without SMSI despite the fact that the number of exposed surface Au atoms was decreased by the SMSI. In addition, the oxidative esterification reaction proceeded even though the Au NPs were fully covered by the sHAP layer when the thickness of the layer was controlled to be less than 1 nm. The substrate can access the surfaces of the Au NPs covered by the thin sHAP layer (<1 nm), and the presence of the sHAP structure in close contact with the Au NPs resulted in significantly higher catalytic activity compared with that for fully exposed Au NPs deposited on the sHAPs. This result suggests that maximizing the contact area between the Au NPs and the sHAP support based on the SMSI enhances the catalytic activity of Au.

Selective formation of acetate intermediate prolongs robust ethylene removal at 0 °C for 15 days

Efficient ethylene (C₂H₄) removal below room temperatures, especially near 0  °C, is of great importance to suppress that the vegetables and fruits spoil during cold-chain transportation and storage. However, no catalysts have been developed to fulfill the longer-than-2-h C₂H₄ removal at this low temperature effectively. Here we prepare gold-platinum (Au-Pt) nanoalloy catalysts that show robust C₂H₄ (of 50 ppm) removal capacity at 0 °C for 15 days (360 h). We find, by virtue of operando Fourier transformed infrared spectroscopy and online temperature-programmed desorption equipped mass spectrometry, that the Au-Pt nanoalloys favor the formation of acetate from selective C₂H₄ oxidation. And this on-site-formed acetate intermediate would partially cover the catalyst surface at 0 °C, thus exposing active sites to prolong the continuous and effective C₂H₄ removal. We also demonstrate, by heat treatment, that the performance of the used catalysts will be fully recovered for at least two times.

Development of Experimental Multi-Robot System for Network Connectivity Controls

This paper reports some results of network connectivity control experiments using a multi-robot system which we developed. Although a lot of connectivity control algorithms for a multi-robot network are proposed, almost all of them are verified only on computer simulations or using experimental robots with centralized sensors and controllers. To execute experimental verifications of connectivity control algorithms on a distributed robotic system, we developed an experimental multi-robot system. Hardware installed on the robot and information flow from sensors to actuators are detailed. Some results of measurement experiments are shown to estimate accuracy to detect a neighbor position. Then, results of connectivity control experiments using the developed multi-robot system are discussed.

POS0675 IMPACT OF PAST USE OF DISEASE MODIFYING ANTI-RHEUMATIC DRUGS ON JAK INHIBITOR TREATMENT FOR RHEUMATOID ARTHRITIS - DATA FROM THE FUKUI ISHIKAWA TOYAMA DATABASE OF RHEUMATOID ARTHRITIS

Background

Currently, five types of Janus kinase inhibitors (JAKis) are used for rheumatoid arthritis (RA) treatment. The number of cases in which multiple JAKis have been prescribed is increasing. However, the real-world efficacy and safety of JAKis and related factors require further evaluation.

Objectives

The primary objective of this study was to elucidate the impact of past use of disease-modifying anti-rheumatic drugs on RA treatment using JAKis. The secondary objective was to investigate the safety profiles of these agents in a real-world setting.

Methods

Of the 303 JAKi-treated patients in the Fukui Ishikawa Toyama Database of RA included in this study, 30 had switched from one JAKi to another (JJ group), 214 switched from a biologic agent to a JAKi (BJ group), and 47 were naïve to either biologics or JAKis (NJ group). We compared baseline factors, treatment response, and JAKi continuation rates among the three groups. Factors related to JAKi discontinuation were assessed using Cox regression analysis. Furthermore, we investigated adverse events and reported them using exposure-adjusted incidence rates (EAIR; incidence rates per 100 patient-years).

Results

Data from the 303 cases were analyzed (mean age = 63.6 years; female, 82%; mean RA duration, 176 months). Of the 303 patients, 118, 106, 50, and 29 were treated with tofacitinib, baricitinib, peficitinib, and upadacitinib, respectively, on initial observation. Rate of concomitant use with methotrexate and prednisolone was 52% and 49%, respectively.

Regarding efficacy, no significant differences were observed among the three groups in terms of treatment response and JAKi continuation rates, except for the 6-month treatment response between the JJ and NJ groups. Cox regression analysis of the 303 cases revealed that only past use of JAKis during the disease history was significantly associated with JAKi discontinuation. The Kaplan–Meier method showed that patients who previously used JAKis had significantly shorter median JAKi treatment duration than those without such a history (20.9 vs. 54.7 months; p = 0.012). Treatment response was significantly poor in patients who had previously used JAKis, especially 6 months after treatment initiation.

In terms of safety, the total exposure period for the 303 cases was 495 person-years, and the total number of adverse events was 161 (EAIR, 32.5). There were 12 cases (EAIR, 2.5) of serious infections, 23 cases (EAIR, 5.1) of herpes zoster, 7 cases (EAIR, 1.4) of malignant tumors, and 4 cases (EAIR, 0.8) of MACE. Adverse events led to JAKi discontinuation in 34 patients (EAIR, 6.9); the main causes of adverse events leading to treatment discontinuation were infectious diseases in 10 cases (EAIR, 2) and neoplasms in 4 cases (EAIR, 0.8). Within 1 year of initiating JAKi therapy, 21 patients discontinued treatment owing to adverse events, which accounted for 27% of the reasons for treatment discontinuation.

We also investigated cases of JAKi dose reduction, observed in 42 of the 303 cases. Among them, 10 patients required a re-increase in the JAKi dose, and 13 patients (56.5%) were able to maintain the reduced dose for more than 1 year. The remaining 19 patients were excluded from the analysis because the treatment duration at the lower dose had not exceeded 1 year at the time of data extraction. No difference in disease activity at the time of dose reduction was observed between those who maintained the new dose and those who did not (mean DAS28-CRP: 1.48 ± 0.26 vs. 1.89 ± 0.62).

Conclusion

Past use of JAKis may contribute to decreased response and continuation rates for JAKi treatment. In this study, conducted in Japan, development of herpes zoster was found to the most frequent adverse event among the priority survey items.

Acknowledgements

I have no acknowledgements to declare.

Disclosure of Interests

None declared

Transesterification of Ethyl-10-undecenoate Using a Cu-Deposited V2O5 Catalyst as a Model Reaction for Efficient Conversion of Plant Oils to Monomers and Fine Chemicals

Transesterification of ethyl-10-undecenoate (derived from castor oil) with 1,4-cyclohexanedimethanol over a recyclable Cu-deposited V₂O₅ catalyst afforded 1,ω-diene, the corresponding cyclohexane-1,4-diylbis(methylene) bis(undec-10-enoate), a promising monomer for the synthesis of biobased polyesters, in an efficient manner. Deposition of Cu plays an important role in proceeding the reaction with high selectivity, and both the activity and the selectivity are preserved for five recycled runs by the addition of the substrates. The present catalyst was effective for transesterification with other alcohols, especially primary alcohols, demonstrating a possibility of using this catalyst for efficient conversion of plant oil to various fine chemicals.

Praseodymia–titania mixed oxide supported gold as efficient water gas shift catalyst: modulated by the mixing ratio of oxides

Modulating the active sites for controllable tuning of the catalytic activity has been the goal of much research, however, this remains challenging. The O vacancy is well known as an active site in reducible oxides. To modify the activity of O vacancies in praseodymia, we synthesized a series of praseodymia–titania mixed oxides. Varying the Pr : Ti mole ratio (2 : 1, 1 : 2, 1 : 1, 1 : 4) allows us to control the electronic interactions between Au, Pr and Ti cations and the local chemical environment of the O vacancies. These effects have been studied study by X-ray photoelectron spectroscopy (XPS), CO diffuse reflectance Fourier transform infrared spectroscopy (CO-DRIFTS) and temperature-programmed reduction (CO-TPR, H₂-TPR). The water gas shift reaction (WGSR) was used as a benchmark reaction to test the catalytic performance of different praseodymia–titania supported Au. Among them, Au/Pr₁Ti₂O_x was identified to exhibit the highest activity, with a CO conversion of 75% at 300 °C, which is about 3.7 times that of Au/TiO₂ and Au/PrO_x. The Au/Pr₁Ti₂O_x also exhibited excellent stability, with the conversion after 40 h time-on-stream at 300 °C still being 67%. An optimal ratio of Pr content (Pr : Ti 1 : 2) is necessary for improving the surface oxygen mobility and oxygen exchange capability, a higher Pr content leads to more O vacancies, however with lower activity. This study presents a new route for modulating the active defect sites in mixed oxides which could also be extended to other heterogeneous catalysis systems.

Schematic illustration of H₂O activation on the Pr-TiO_x support and the following reaction with CO in the Au–oxide interface.

Anti-inflammatory effect of gold nanoparticles supported on metal oxides

Gold (Au) can be deposited as nanoparticles (NPs) smaller than 10 nm in diameter on a variety of metal oxide (MOx) NPs. Au/MOx have high catalytic performance and selective oxidation capacity which could have implications in terms of biological activity, and more specifically in modulation of the inflammatory reaction. Therefore, the aim of this study was to examine the effect of Au/TiO₂, Au/ZrO₂ and Au/CeO₂ on viability, phagocytic capacity and inflammatory profile (TNF-α and IL-1β secretion) of murine macrophages. The most important result of this study is an anti-inflammatory effect of Au/MOx depending on the MOx nature with particle internalization and no alteration of cell viability and phagocytosis. The effect was dependent on the MOx NPs chemical nature (Au/TiO₂ > Au/ZrO₂ > Au/CeO₂ if we consider the number of cytokines whose concentration was reduced by the NPs), and on the inflammatory mediator considered. The effect of Au/TiO₂ NPs was not related to Au NPs size (at least in the case of Au/TiO₂ NPs in the range of 3-8 nm). To the best of our knowledge, this is the first demonstration of an anti-inflammatory effect of Au/MOx.

Catalytic Activities of Various Niobium Oxides for Hydrogen Absorption/Desorption Reactions of Magnesium

Five types of niobium(V) oxides (Nb₂O₅) were synthesized by hydrothermal and heat treatment processes, and their structural properties and catalytic activities for the hydrogen absorption/desorption reactions of magnesium were characterized. The synthesized Nb oxides were dispersed on magnesium hydride (MgH₂), a typical hydrogen storage material, using the ball-milling method. All the synthesized Nb oxides improved the reaction kinetics of the hydrogen desorption/absorption reactions. The catalytic activities for the hydrogen desorption were comparable, while the hydrogen absorption rates were significantly different for each synthesized Nb oxide. This difference can be explained by the structural stability of Nb₂O₅, which is related to the formation of a catalytically active state by the reduction of Nb₂O₅ during the ball-milling process. Notably, the highest catalytic effect was observed for Nb₂O₅ with a highly crystalline pyrochlore structure and a low specific surface area, suggesting that pyrochlore Nb₂O₅ is a metastable phase. However, only the amorphous Nb oxide was out of order, even though there is a report on the high catalytic activity of amorphous Nb oxide. This is attributed to the initial condensed state of amorphous Nb oxide, because particle size affects the dispersion state on the MgH₂ surface, which is also important for obtaining high catalytic activity. Thus, it is concluded that Nb₂O₅ with lower stability of the crystal structure and smaller particle size shows better catalysis for both hydrogen desorption and absorption reactions.

Dehydrative Allylation of Amine with Allyl Alcohol by Titanium Oxide Supported Molybdenum Oxide Catalyst

The dehydrative allylation from allyl alcohol with amines to generate various allyl amines by MoO3/TiO2 solid catalyst is described. The catalyst can be reused at least three times without a decrease of activity.

A zeolitic vanadotungstate family with structural diversity and ultrahigh porosity for catalysis

Design of the structure and composition of crystalline microporous inorganic oxides is of great importance in catalysis. Developing new zeolites is one approach towards this design because of the tunable pore system and high thermal stability. Zeolites are limited to main group elements, which limits their applications in redox catalysis. Another promising choice is zeolitic transition metal oxides providing both porosity and redox activity, thereby further expanding the diversity of porous materials. However, the examples of zeolitic transition metal oxides are rare. Here, we report a new class of zeolitic vanadotungstates with tunable frameworks exhibiting a large porosity and redox activity. The assembly of [W₄O₁₆]⁸⁻ units with VO²⁺ forms two isomeric porous frameworks. Owing to the complex redox properties and open porosity, the vanadotungstates efficiently catalyse the selective reduction of NO by NH₃. This finding provides an opportunity for design and synthesis of inorganic multifunctional materials for future catalytic applications.

Zeolitic transition metal oxides provide both porosity and redox activity, thereby further expanding the diversity of porous materials, but their design and development remain rare. Here, the authors report a new class of zeolitic vanadotungstates with tunable frameworks exhibiting a large porosity and redox activity.

Sex-specific relevance of diabetes to occlusive vascular and other mortality: a collaborative meta-analysis of individual data from 980 793 adults from 68 prospective studies

BACKGROUND

Several studies have shown that diabetes confers a higher relative risk of vascular mortality among women than among men, but whether this increased relative risk in women exists across age groups and within defined levels of other risk factors is uncertain. We aimed to determine whether differences in established risk factors, such as blood pressure, BMI, smoking, and cholesterol, explain the higher relative risks of vascular mortality among women than among men.

METHODS

In our meta-analysis, we obtained individual participant-level data from studies included in the Prospective Studies Collaboration and the Asia Pacific Cohort Studies Collaboration that had obtained baseline information on age, sex, diabetes, total cholesterol, blood pressure, tobacco use, height, and weight. Data on causes of death were obtained from medical death certificates. We used Cox regression models to assess the relevance of diabetes (any type) to occlusive vascular mortality (ischaemic heart disease, ischaemic stroke, or other atherosclerotic deaths) by age, sex, and other major vascular risk factors, and to assess whether the associations of blood pressure, total cholesterol, and body-mass index (BMI) to occlusive vascular mortality are modified by diabetes.

RESULTS

Individual participant-level data were analysed from 980 793 adults. During 9·8 million person-years of follow-up, among participants aged between 35 and 89 years, 19 686 (25·6%) of 76 965 deaths were attributed to occlusive vascular disease. After controlling for major vascular risk factors, diabetes roughly doubled occlusive vascular mortality risk among men (death rate ratio [RR] 2·10, 95% CI 1·97-2·24) and tripled risk among women (3·00, 2·71-3·33; χ2 test for heterogeneity p<0·0001). For both sexes combined, the occlusive vascular death RRs were higher in younger individuals (aged 35-59 years: 2·60, 2·30-2·94) than in older individuals (aged 70-89 years: 2·01, 1·85-2·19; p=0·0001 for trend across age groups), and, across age groups, the death RRs were higher among women than among men. Therefore, women aged 35-59 years had the highest death RR across all age and sex groups (5·55, 4·15-7·44). However, since underlying confounder-adjusted occlusive vascular mortality rates at any age were higher in men than in women, the adjusted absolute excess occlusive vascular mortality associated with diabetes was similar for men and women. At ages 35-59 years, the excess absolute risk was 0·05% (95% CI 0·03-0·07) per year in women compared with 0·08% (0·05-0·10) per year in men; the corresponding excess at ages 70-89 years was 1·08% (0·84-1·32) per year in women and 0·91% (0·77-1·05) per year in men. Total cholesterol, blood pressure, and BMI each showed continuous log-linear associations with occlusive vascular mortality that were similar among individuals with and without diabetes across both sexes.

INTERPRETATION

Independent of other major vascular risk factors, diabetes substantially increased vascular risk in both men and women. Lifestyle changes to reduce smoking and obesity and use of cost-effective drugs that target major vascular risks (eg, statins and antihypertensive drugs) are important in both men and women with diabetes, but might not reduce the relative excess risk of occlusive vascular disease in women with diabetes, which remains unexplained.

FUNDING

UK Medical Research Council, British Heart Foundation, Cancer Research UK, European Union BIOMED programme, and National Institute on Aging (US National Institutes of Health).

Versatile etherification of alcohols with allyl alcohol by a titanium oxide-supported molybdenum oxide catalyst: gradual generation from titanium oxide and molybdenum oxide

A sustainable method to synthesize allyl ethers from allyl alcohol by the simple mixing of TiO₂ and MoO₃ catalysts.