Mitigating the Poisoning Effect of Formate during CO <sub>2</sub> Hydrogenation to Methanol over Co-Containing Dual-Atom Oxide Catalysts
Nazmul Hasan MD Dostagir, Carlo Robert Tomuschat, K. Oshiro, Min Gao, Jun‐ya Hasegawa, Atsushi Fukuoka, Abhijit Shrotri
Abstract
High Resolution Image Download MS PowerPoint Slide During the hydrogenation of CO 2 to methanol over mixed-oxide catalysts, the strong adsorption of CO 2 and formate poses a barrier for H 2 dissociation, limiting methanol selectivity and productivity. Here we show that by using Co-containing dual-atom oxide catalysts, the poisoning effect can be countered by separating the site for H 2 dissociation and the adsorption of intermediates. We synthesized a Co- and In-doped ZrO 2 catalyst (Co–In–ZrO 2 ) containing atomically dispersed Co and In species. Catalyst characterization showed that Co and In atoms were atomically dispersed and were in proximity to each other owing to a random distribution. During the CO 2 hydrogenation reaction, the Co atom was responsible for the adsorption of CO 2 and formate species, while the nearby In atoms promoted the hydrogenation of adsorbed intermediates. The cooperative effect increased the methanol selectivity to 86% over the dual-atom catalyst, and methanol productivity increased 2-fold in comparison to single-atom catalysts. This cooperative effect was extended to Co–Zn and Co–Ga doped ZrO 2 catalysts. This work presents a different approach to designing mixed-oxide catalysts for CO 2 hydrogenation based on the preferential adsorption of substrates and intermediates instead of promoting H 2 dissociation to mitigate the poisonous effects of substrates and intermediates.