CO<sub>2</sub> Hydrogenation to Methanol on CoIn<sub>2</sub>/In<sub>2</sub>O<sub>3</sub>: The Role of the Alloy/Oxide Interface in Driving Catalytic Activity and Selectivity
Biao Gao, Bin Yang, Kazuto Hatakeyama, Yifu Wang, Longtai Li, Shintaro Ida, Tatsumi Ishihara, Limin Guo
Abstract
CO 2 catalytic hydrogenation to methanol is promising for CO 2 utilization. In 2 O 3 -based catalysts are attracting much attention because of their high methanol selectivity. However, a low CO 2 conversion rate limits the overall methanol yield. Herein, we developed the interface of the CoIn 2 alloy and In 2 O 3 oxide as a CoIn 2 /In 2 O 3 catalyst and successfully achieved high performance for the hydrogenation of CO 2 to methanol. Experimental and theoretical results indicated that the alloy/oxide interface is stable during the reaction atmosphere; the high performance arising from the electronic interaction between CoIn 2 and In 2 O 3, which improves the electron density at the CoIn 2 interface, facilitates H 2 dissociation, CO 2 adsorption, and the hydrogenation of formate intermediates to methanol, which justifies the sustained high methanol selectivity and production rate. The optimized catalyst showed a methanol selectivity up to 74% and a high methanol space-time yield up to 0.69 g MeOH g cat –1 h –1 at 5.0 MPa, H 2 /CO 2 = 3:1, 300 °C and 36,000 mLg cat –1 h –1 .