Elaborated Reaction Pathway of Photothermal Catalytic CO₂ Conversion with H₂O on Gallium Oxide‐Decorated and ‐Defective Surfaces

Abstract

Ga2O3‐decorated and ‐defective surface models based on anatase TiO2 have been established. The thermodynamic reaction pathways, including protonation, deoxygenation and hydroxylation steps, during CO2 conversion with H2O to C1 products were calculated. The calculation results demonstrate that a Ga2O3 cocatalyst enhances the selective adsorption of CO2 and slightly weakens the competitive adsorption of H2O. The promotion effect of Ga2O3 on the subsequent reaction depends on the availability of protons and electrons. Free‐energy calculations revealed that the basic functional site generated by Ga2O3 not only suppresses the back reaction of the OH group after H2O directly provides protons but also maintains the surface defect oxygen vacancy (VO), which promotes the reaction thermodynamics but tends to be consumed in the process. Additionally, Ga2O3 decoration promotes VO formation, and the coexistence of Ga2O3 and VO further decreases the reaction rate‐determining step energy barrier, promoting C1 production.

Unraveling active sites regulation and temperature-dependent thermodynamic mechanism in photothermocatalytic CO2 conversion with H2O

“…It results in a variety of intermediate species and a complex reaction process. The elaborated thermodynamic reaction network of CO 2 conversion with H 2 O on aTiO 2 (101)-based surface has been reported in our previous work 56 . To observe its temperaturedependent characteristics, here the reaction paths of CO 2 with H 2 O to C 1 products (mainly CO, CH 3 OH and CH 4 ) on pure aTiO 2 (101) surface at 100~400 °C were calculated, and the energy barriers comparison of all intermediate steps were shown in Supplementary Fig.…”

“…The enhancement of the basic sites introduced via doping for subsequent CO 2 conversion reactions relied on the availability of protons and electrons. The collaborative presence of synergistic surface oxygen defects and basic sites worked in tandem to amplify the reaction's thermodynamics, facilitating the multi-electron conversion of CO 2 to yield C1 products 56 . Based on the efficacy of La 2 O 3 , Al 2 O 3 , and Ga 2 O 3 in augmenting the adsorption and activation of CO 2 molecules and H atoms, comprehensive calculations of the entire thermodynamic reaction paths for photothermal catalytic CO 2 conversion to C 1 products (CO, CH 3 OH, and CH 4 ) at varying temperatures were performed on the respective defective surfaces doped with these compounds.…”

“…The modified metal oxide semiconductor systems were constructed based on our previous theoretical and experimental studies 56,77,78 . Typically, TiO 2based catalysts can maintain a stable crystal form of anatase at temperatures below approximately 450 °C.…”

Understanding the light-induced oxygen vacancy in the photochemical conversion

“…Therefore, a stable and precise in-situ reaction cell is more important in this regard. Lastly, the theoretical calculations could also be employed as a powerful tool in support of the in-situ measurement results and provide deeper insights into the reaction mechanism [76][77][78]80].…”