Tuning product selectivity of CO ₂ hydrogenation by OH groups on Pt/ γ‐AlOOH and Pt/ γ‐Al ₂ O ₃ catalysts

Abstract Herein, we explore how OH groups on Pt/γ‐AlOOH and Pt/γ‐Al 2 O 3 catalysts affect CO 2 hydrogenation with H 2 at temperatures from 250°C to 400°C. OH groups are abundant on γ‐AlOOH, but rare at Pt‐(γ‐AlOOH) interface which is the most favorable site for CO 2 conversion on Pt/γ‐AlOOH. This makes CO 2 hydrogenation on Pt/γ‐AlOOH form CO weakly bonding to γ‐AlOOH, which prefers to desorption from Pt/γ‐AlOOH rather than further conversion, thus enhancing CO production on Pt/γ‐AlOOH. Different from Pt/γ‐AlOOH, OH groups are abundant at Pt‐(γ‐Al 2 O 3 ) interface which is the most favorable site for CO 2 conversion on Pt/γ‐Al 2 O 3 . This promotes CO 2 hydrogenation on Pt/γ‐Al 2 O 3 to form CO strongly bonding to Pt, which prefers to further hydrogenation to CH 4 , and thereby increases CH 4 selectivity on Pt/γ‐Al 2 O 3 . Therefore, the OH groups at metal‐support interface are crucial factor influencing product distribution, and must be considered seriously when fabricating catalysts.