Improvement of the activity of CO2 methanation in a hybrid plasma-catalytic process in varying catalyst particle size or under pressure

Preparation of three-dimensional ordered macroporous Ag/LaFeO3 and heterogeneous photo-Fenton degradation of penicillin G potassium

3DOMLaFeO3 was prepared by template method combined with sol-gel method using monodisperse polystyrene (PS) microspheres as template, and Ag/3DOMLaFeO3 perovskite catalyst was prepared by impregnation method combined with sodium borohydride reduction method. The catalysts were characterised by means of TG, XRD, SEM, BET, XPS, UV-vis DRS, etc. The photo-Fenton catalytic performance, stability and catalytic reaction mechanism of Ag/3DOMLaFeO3 were studied with penicillin G potassium (PEN G) as the model pollutant. The results indicated that the as-prepared Ag/3DOMLaFeO3 exhibited a three-dimensional ordered macroporous (3DOM) structure, and the light capture and mass transfer were enhanced through abundant pores and large specific surface area. Based on the surface plasmon resonance effect (SPR), Ag loading enhanced the absorption of the material in the visible light region, and inhibited the recombination of photogenerated carriers, which improved the photocatalytic performance of 3DOMLaFeO3 under visible light. Under the conditions of hydrogen peroxide dosage of 1.5 mL·L-1, initial pH of 5, PEN G initial concentration of 100 mg·L-1, catalyst dosage of 300 mg·L-1, xenon lamp irradiation, the degration ratio of PEN G and the removal rate of TOC reached 99.99% and 85.45% within 120 min, respectively. In addition, it had a wide range of pH application, excellent stability and practical application value. The quenching experiment and ESR test showed that ·OH and ·O2- were the reasons for high catalytic degradation. The least square method was used to fit the experimental data, and the results displayed that the degradation of PEN G was approximately in line with the first-order kinetic reaction.

Recent advances in energy efficiency optimization methods for plasma CO2 conversion

Efforts to develop efficient methods for converting carbon dioxide (CO2) have drawn mounting interest due to incremental concerns over carbon emissions. Non-thermal plasma (NTP) technology has shown promise in this regard by producing numerous reactive substances at relatively low temperatures. However, an analysis of relevant literature reveals an underwhelming level of overall energy efficiency for this technology and an insufficient level of attention being paid to it. It is crucial to put forward more effective energy-saving schemes based on a comprehensive analysis of past research results to promote sustained development. This review highlights the latest advances in pertinent energy efficiency optimization studies and outlines state-of-the-art methods. In terms of energy efficiency optimization for plasma CO2 conversion, a comparison is made among different research results in four aspects as follows. Specifically, this study analyzes reactor structure optimization in terms of discharge characteristic, flow field, and plasma contact area; discusses pathways of heat transfer optimization to suppress the competing reaction; and explores catalyst optimization in terms of active sites, calcination temperature, and product selectivity; examines the potential of utilizing solar energy for clean energy applications. The analysis of energy efficiency data indicates an overall improvement when the aforementioned optimization measures are applied, which is essential to validate the effectiveness of each method. Finally, this paper discusses the potential difficulties and future research areas of NTP technology. Urgent further research is imperative on energy efficiency optimization methods for potential large-scale industrial applications in the future.

On the Effect of Cobalt Promotion over Ni/CeO2 Catalyst for CO2 Thermal and Plasma Assisted Methanation

In recent years, carbon dioxide hydrogenation leading to synthetic fuels and value-added molecules has been proposed as a promising technology for stabilizing anthropogenic greenhouse gas emissions. Methanation or Sabatier are possible reactions to valorize the CO2. In the present work, thermal CO2 methanation and non-thermal plasma (NTP)-assisted CO2 methanation was performed over 15Ni/CeO2 promoted with 1 and 5 wt% of cobalt. The promotion effect of cobalt is proven both for plasma and thermal reaction and can mostly be linked with the basic properties of the materials.

Plasma-Catalytic Process of Hydrogen Production from Mixture of Methanol and Water

In the present work the process of hydrogen production was conducted in the plasma-catalytic reactor, the substrates were first treated with plasma and then introduced into the catalyst bed. Plasma was produced by a spark discharge. The discharge power ranged from 15 to 46 W. The catalyst was metallic nickel supported on Al2O3. The catalyst was active from a temperature of 400 °C. The substrate flow rate was 1 mol/h of water and 1 mol/h of methanol. The process generated H2, CO, CO2 and CH4. The gas which formed the greatest amount was H2. Its concentration in the gas was ~60%. The conversion of methanol and the production of hydrogen in the plasma-catalytic reactor were higher than in the plasma and catalytic reactors. The synergy effect of the interaction of two environments, i.e., plasma and the catalyst, was observed. The highest hydrogen production was 1.38 mol/h and the highest methanol conversion was 64%. The increased in the discharge power resulted in increasing methanol conversion and hydrogen production.

Ni-Containing Catalysts

Murray Raney used Nickel for the first time as a hydrogenation catalyst over one century ago [...]