This study is led by Prof. Peng Gao and Prof. Shenggang Li (CAS Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute).
In this paper, the hydrogenation metals (Co, Ni and Cu) promoted In 2 O 3 catalysts with a similar loading of 1 wt.% were prepared by the hydrothermal method. It was found that the Ni-promoted In 2 O 3 catalyst with high dispersion possesses the largest amount of oxygen vacancies and the strongest ability for H 2 activation, and exhibited the highest CO 2 conversion and STY of CH 3 OH, which reached 0.390 g MeOH g cat −1 h −1 with CH 3 OH selectivity of 68.7%. In addition, the Ni-promoted In 2 O 3 catalyst exhibits very stable performance over 120 h on stream, which suggests the promising prospect for industrial applications. Moreover, a series of Ni modified In 2 O 3 catalysts with different surface Ni contents were prepared to further investigate the effect of oxygen vacancy properties on the catalytic behavior of CO 2 hydrogenation to methanol. Surface Ni doping was found to promote the formation of oxygen defects on the In 2 O 3 surface, resulting in higher CO 2 reactivity, whereas the Ni-promoted In 2 O 3 catalyst with more subsurface Ni showed higher methanol selectivity and productivity. The catalytic performance of our Ni/In 2 O 3 catalysts was further rationalized by DFT calculations and microkinetic simulations. DFT-based microkinetic simulations show that CO formation is preferred at the oxygen vacancy site on the surface-doped Ni/In 2 O 3 catalyst, whereas CH 3 OH formation is favored at that on the subsurface-doped Ni/In 2 O 3 catalyst especially at relatively low reaction temperatures. This work thus provides theoretical guidance for improving the CO 2 reactivity of In 2 O 3 -based catalysts while maintaining high methanol selectivity.
This study not only provides a better understanding of the effect of transition-metal promoters with high dispersion on the catalytic performance, but also suggests that DFT-based microkinetic simulations can provide reliable prediction on the catalytic activity and product selectivity for the CO 2 hydrogenation to methanol reaction over industrially relevant metal-promoted oxide catalysts, which is crucial for their computer-aided rational design.
See the article:
Nickel-modified In 2 O 3 with inherent oxygen vacancies for CO 2 hydrogenation to methanol
http://engine.scichina.com/doi/10.1007/s11426-023-1929-1
Science China Chemistry