Developing catalysts capable of efficiently utilizing both visible and near-infrared wavelengths of the solar spectrum for CO_(2)hydrogenation has led to growing interest in reduced TiO_(2)materials.Achieving efficien...Developing catalysts capable of efficiently utilizing both visible and near-infrared wavelengths of the solar spectrum for CO_(2)hydrogenation has led to growing interest in reduced TiO_(2)materials.Achieving efficient long-wavelength solar light harvesting requires a high concentration of oxygen vacancies(O_(V)).However,extensive O_(V)formation can lead to atomic rearrangements within TiO_(X),causing a dispersion of O_(V)throughout the material,as opposed to creating localized and distinct O_(V)sites typical of crystalline TiO_(X),which interact directly with reactants.In this study,we synthesized amorphous black TiO_(X)(AM-TiO_(X))catalysts and thoroughly characterized their surface properties,including acidity and the desorption bond strengths of H_(2)and CO_(2).Density functional theory(DFT)simulations were performed to analyze the hydrogen adsorption profile and structural changes in the material due to O_(V)formation.We found that hydrogen mobility on the surface is restricted due to strong hydrogen bonding.The CO_(2)hydrogenation process was investigated using in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS),enabling the development of a reaction pathway to elucidate the catalyst’s selectivity towards CO and the effect of light irradiation on product formation rates.Notably,m-HCO_(3)^(*)formation was favored,with CO and CH_(4)production proceeding primarily via the formate pathway.To enhance catalyst stability against oxidation during reaction,the surface was decorated with Ru particles.The findings of this study are relevant to catalysts that leverage extensive O_(V)formation as a strategy to extend light responsiveness,as well as to the design of catalysts for CO_(2)hydrogenation to CO.展开更多
基金supported by the Second Century Fund(C2F)of Chulalongkorn University,Thailand.
文摘Developing catalysts capable of efficiently utilizing both visible and near-infrared wavelengths of the solar spectrum for CO_(2)hydrogenation has led to growing interest in reduced TiO_(2)materials.Achieving efficient long-wavelength solar light harvesting requires a high concentration of oxygen vacancies(O_(V)).However,extensive O_(V)formation can lead to atomic rearrangements within TiO_(X),causing a dispersion of O_(V)throughout the material,as opposed to creating localized and distinct O_(V)sites typical of crystalline TiO_(X),which interact directly with reactants.In this study,we synthesized amorphous black TiO_(X)(AM-TiO_(X))catalysts and thoroughly characterized their surface properties,including acidity and the desorption bond strengths of H_(2)and CO_(2).Density functional theory(DFT)simulations were performed to analyze the hydrogen adsorption profile and structural changes in the material due to O_(V)formation.We found that hydrogen mobility on the surface is restricted due to strong hydrogen bonding.The CO_(2)hydrogenation process was investigated using in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS),enabling the development of a reaction pathway to elucidate the catalyst’s selectivity towards CO and the effect of light irradiation on product formation rates.Notably,m-HCO_(3)^(*)formation was favored,with CO and CH_(4)production proceeding primarily via the formate pathway.To enhance catalyst stability against oxidation during reaction,the surface was decorated with Ru particles.The findings of this study are relevant to catalysts that leverage extensive O_(V)formation as a strategy to extend light responsiveness,as well as to the design of catalysts for CO_(2)hydrogenation to CO.
