Effect of the preparation method on the hydrogenation activity of Ni/SBA-15 catalysts: Comparison of EDTA complexation and DPU

Acetone Efficient Degradation under Simulated Humid Conditions by Mn-O-Pt Interaction Taming-Triggered Water Dissociation Intensification

As a generally existing component in industrial streams, H2O usually inhibits the catalytic degradation efficiency of volatile organic compounds (VOCs) greatly. Here, we propose a novel strategy that accelerates the H2O dissociation and facilitates positive feedbacks during VOC oxidation by fabricating citric acid (CA)-assisted Pt(K)-Mn2O3/SiO2 (Pt-Mn/KS-xCA). Results reveal that the complexation of carboxyl groups of citric acid with Mn cations leads to the formation of small Mn2O3 (4.1 ± 0.2 nm) and further enhances the Mn-O-Pt interaction (strengthened by the Si-O-Mn interaction), which can transfer more electrons from Pt-Mn/KS-6CA to H2O, thus facilitating its breaking of covalent bonds. It subsequently produces abundant surface hydroxyl groups, improving the adsorption and activation abilities of acetone reactant and ethanol intermediate. Attributing to these, the acetone turnover frequency value of Pt-Mn/KS-6CA is 1.8 times higher than that of Pt-Mn/KS at 160 °C, and this multiple changes to 6.3 times in the presence of H2O. Remarkably, acetone conversion over Pt-Mn/KS-6CA increases by up to 14% in the presence of H2O; but it decreases by up to 26% for Pt-Mn/KS due to its weak dissociation ability and high adsorption capacity toward H2O. This work sheds new insights into the design of highly efficient catalytic materials for VOC degradation under humid conditions.

Household food waste conversion to biohydrogen via steam gasification over copper and nickel-loaded SBA-15 catalysts

Household food waste (FW) was converted into biohydrogen-rich gas via steam gasification over Ni and bimetallic Ni (Cu-Ni and Co-Ni) catalysts supported on mesoporous SBA-15. The effect of catalyst method on steam gasification efficiency of each catalyst was investigated using incipient wetness impregnation, deposition precipitation, and ethylenediaminetetraacetic acid metal complex impregnation methods. H₂-TPR confirmed the synergistic interaction of the dopants (Co and Cu) and Ni. Furthermore, XRD and HR-TEM revealed that the size of the Ni particle varied depending on the method of catalyst synthesis, confirming the formation of solid solutions in Co- or Cu-doped Ni/SBA-15 catalysts due to dopant insertion into the Ni. Notably, the exceptional activity of the Cu-Ni/SBA-15-EMC catalyst in FW steam gasification was attributed to the fine distribution of the concise Ni nanoparticles (9 nm), which resulted in the highest hydrogen selectivity (62 vol%), gas yield (73.6 wt%). Likewise, Cu-Ni solid solution decreased coke to 0.08 wt%.

Recent Advances in the Applications of Mesoporous Silica in Heterogenous Catalysis

Mesoporous silica is a class of silica material with a large specific surface area, high specific pore volume and meso-sized pores. These properties make mesoporous silica a good choice of...

Naphthalene Hydrogenation Saturation over Ni2P/Al2O3 Catalysts Synthesized by Thermal Decomposition of Hypophosphite

A series of Ni₂P/Al₂O₃ catalysts with different Ni₂P loadings were synthesized via thermal decomposition of hypophosphite and employed for naphthalene hydrogenation saturation. Results showed that Ni₂P loading greatly affected Ni₂P particle size and the number of active sites of the as-synthesized catalysts, which was derived from the variable interaction between POx and Al₂O₃. When the hydrogenation saturation reaction was performed at 300 °C, 4 MPa, a H₂/oil volume ratio of 600, and a liquid hourly space velocity (LHSV) of 3 h^-1, 98% naphthalene conversion and 98% selectivity to decalin were achieved over Ni₂P/Al₂O₃ catalysts with 10 wt % Ni₂P. The superior naphthalene hydrogenation saturation performance was ascribed to the large specific surface area (169 m²·g^-1), small Ni₂P particle size (3.8 nm), and the high number of exposed active sites (CO sorption 30 μmol·g^-1), which were beneficial to the adsorption and diffusion of the reactant molecules on the catalyst.