Catalytic behavior of metal catalysts in high-temperature RWGS reaction: In-situ FT-IR experiments and first-principles calculations

Abstract

High-temperature chemical reactions are ubiquitous in (electro) chemical applications designed to meet the growing demands of environmental and energy protection. However, the fundamental understanding and optimization of such reactions are great challenges because they are hampered by the spontaneous, dynamic, and high-temperature conditions. Here, we investigated the roles of metal catalysts (Pd, Ni, Cu, and Ag) in the high-temperature reverse water-gas shift (RWGS) reaction using in-situ surface analyses and density functional theory (DFT) calculations. Catalysts were prepared by the deposition-precipitation method with urea hydrolysis and freeze-drying. Most metals show a maximum catalytic activity during the RWGS reaction (reaching the thermodynamic conversion limit) with formate groups as an intermediate adsorbed species, while Ag metal has limited activity with the carbonate species on its surface. According to DFT calculations, such carbonate groups result from the suppressed dissociation and adsorption of hydrogen on the Ag surface, which is in good agreement with the experimental RWGS results.

Noble-metal-free and Pt nanoparticles-loaded, mesoporous oxides as efficient catalysts for CO2 hydrogenation and dry reforming with methane

“…CO + H 2 O    kJ mol  However, CO 2 hydrogenation is an endothermic reaction and requires high operation temperature [10]. Various metals such as Pt [11][12][13][14], Pd [15][16][17][18], Rh [19][20][21][22][23][24] and Au [25,26],…”

Insight into CO 2 reforming of CH 4 via NiO /dolomite catalysts for production of H 2 rich syngas

“…This might be due to some parallel reaction such as reversed water-gas shift (RWGS) reaction as reported by Choi et al (2007). 38 On the other hand, Figure 1D showed the same pattern of CO 2 conversion and CO selectivity as the temperature gave the same effect on catalytic performance. Overall, doping of nickel oxide onto the surface of dolomite is believed to increase the catalytic conversion of CH 4 but slightly reduced the CO 2 conversion, which affect the H 2 and CO selectivity.…”

Fabrication of Black In2O3 with Dense Oxygen Vacancy through Dual Functional Carbon Doping for Enhancing Photothermal CO2 Hydrogenation

“…Simultaneously, the peak at 2107 cm −1 and 1643 cm −1 were the diagnostic vibrational modes of CO and H 2 O respectively, indicating the reaction pathway that features CO* as the intermediate from carboxyl through the RWGS reaction [51][52][53][54] . In general,…”