CO2 hydrogenation to methanol over Pd/In2O3: effects of Pd and oxygen vacancy

A novel Core–Shell structured CuIn@SiO2 catalyst for CO2 hydrogenation to methanol

“…Moreover, it can be found from Figure that In@SiO 2 has the high‐temperature desorption peak at 380°C, which is much less than that of CuIn@SiO 2 (475°C) or CuIn/SiO 2 (550°C). As reported by previous researchers, In 2 O 3 ‐based catalysts have two CO 2 desorption peaks at approximately 430 and 320°C, attributable to oxygen vacancies that are thermally induced (O v1 ) and formed by H 2 reduction (O v2 ), respectively. Nevertheless, in this study just one broad peak at higher temperature can be found for the In@SiO 2 , CuIn@SiO 2 , and CuIn/SiO 2 catalysts, probably due to the overlap of two different peaks.…”

“…For Cu@SiO 2 , only one broad reduction peak is detected at about 250°C, which can be ascribed to CuO species reduction. The onset reduction temperature of In@SiO 2 is around 160°C, and then two peaks appear at about 350 and 500°C, assigned to the reduction of surface and bulk In 2 O 3 , respectively . The bimetallic catalysts exhibit different reduction profiles from the corresponding individual metal oxides; however, two reduction peaks are still found for the two bimetallic catalysts.…”

“…Martin et al found that ZrO 2 supported In 2 O 3 catalyst had high CO 2 hydrogenation activity, satisfactory CH 3 OH selectivity and remarkable stability for 1000 h on stream. Rui et al prepared highly dispersed Pd/In 2 O 3 catalyst using peptide as a template for CH 3 OH synthesis from CO 2 hydrogenation, with CO 2 conversion >20%, methanol selectivity >70% and CH 3 OH space–time yield up to 27.8 mmol·h −1 ·g cat −1 at 300°C and 5 MPa. They also observed that both Pd‐In 2 O 3 interfacial sites and oxygen vacancies played important roles in activation and hydrogenation of CO 2 to CH 3 OH.…”

Photoinduced Defect Engineering: Enhanced Photothermal Catalytic Performance of 2D Black In2O3−x Nanosheets with Bifunctional Oxygen Vacancies

“…Its catalytic active sites promote the adsorption and activation for thermochemical CO 2 hydrogenation, but the wide band (2.8 eV) is unfavorable for photothermal conversion for a long time. In order to expanding the limited optical adsorption of In 2 O 3 under sunlight, there have been persistent efforts to alter the material composition of In 2 O 3 , such as element doping, precious metals supporting, and nanostructured substance coating . For example, when Bi metallic dopants are introduced, the optical adsorption can be modified as the result of electronic hybridization between Bi 6s and O 2p orbitals, upwardly shifting the valence band (VB) and consequently reducing bandgap .…”

Hydrogen Utilization in Green Fuel Synthesis via CO2 Conversion to Methanol over New Cu-Based Catalysts

“…Prompted by seeking better performing formulations, many authors have explored new catalytic compositions, active in the CO 2 hydrogenation, alternative to the copper-based, such as combinations of Pd [13,14], Au [10,15], or Mo 2 C [16,17]. Nevertheless, copper-based catalysts still remain the most suitable catalysts for commercial applications [18].…”