Kinetics of H2 Adsorption at the Metal–Support Interface of Au/TiO2 Catalysts Probed by Broad Background IR Absorbance
H2 adsorption on Au catalysts is weak and reversible, making it difficult to quantitatively study. We demonstrate H2 adsorption on Au/TiO2 catalysts results in electron transfer to the support, inducing shifts in the FTIR background. This broad background absorbance (BBA) signal is used to quantify H2 adsorption; adsorption equilibrium constants are comparable to volumetric adsorption measurements. H2 adsorption kinetics measured with the BBA show a lower Eapp value (23 kJ mol−1) for H2 adsorption than previously reported from proxy H/D exchange (33 kJ mol−1). We also identify a previously unreported H-O-H bending vibration associated with proton adsorption on electronically distinct Ti-OH metal-support interface sites, providing new insight into the nature and dynamics of H2 adsorption at the Au/TiO2 interface.
Mahdavi-Shakib, A., Kumar, K. B. S., Whittaker, T. N., Xie, T., Grabow, L. C., Rioux, R. M., & Chandler, B. D. (2021). Kinetics of H2 adsorption at the metal-support interface of Au/TiO2 catalysts probed by broad background IR absorbance. Angewandte Chemie - International Edition, 60(14), 7735-7743. http://doi.org/10.1002/anie.202013359
Angewandte Chemie - International Edition