Bifunctional hydroformylation on heterogeneous Rh-WOx pair site catalysts

Insoo Ro; Ji Qi; Seungyeon Lee; Mingjie Xu; Xingxu Yan; Zhenhua Xie; Gregory Zakem; Austin Morales; Jingguang G Chen; Xiaoqing Pan; Dionisios G Vlachos; Stavros Caratzoulas; Phillip Christopher

doi:10.1038/s41586-022-05075-4

Bifunctional hydroformylation on heterogeneous Rh-WO_x pair site catalysts

Nature. 2022 Sep;609(7926):287-292. doi: 10.1038/s41586-022-05075-4. Epub 2022 Sep 7.

Authors

Insoo Ro^#^{1

2

3}, Ji Qi^#^{1

3}, Seungyeon Lee^#^{3

4}, Mingjie Xu⁵, Xingxu Yan⁵, Zhenhua Xie^{6

7}, Gregory Zakem¹, Austin Morales¹, Jingguang G Chen^{6

7}, Xiaoqing Pan^{5

8

9}, Dionisios G Vlachos^{3

4}, Stavros Caratzoulas⁴, Phillip Christopher^{10

11}

Affiliations

¹ Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA.
² Department of Chemical and Biomolecular Engineering, Seoul National University of Science and Technology, Seoul, Republic of Korea.
³ Catalysis Center for Energy Innovation, Newark, DE, USA.
⁴ Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, USA.
⁵ Department of Materials Science and Engineering, University of California Irvine, Irvine, CA, USA.
⁶ Chemistry Division, Brookhaven National Laboratory, Upton, NY, USA.
⁷ Department of Chemical Engineering, Columbia University, New York, NY, USA.
⁸ Department of Physics and Astronomy, University of California, Irvine, Irvine, CA, USA.
⁹ Irvine Materials Research Institute (IMRI), University of California Irvine, Irvine, Irvine, CA, USA.
¹⁰ Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA. pchristopher@ucsb.edu.
¹¹ Catalysis Center for Energy Innovation, Newark, DE, USA. pchristopher@ucsb.edu.

^# Contributed equally.

PMID: 36071187
DOI: 10.1038/s41586-022-05075-4

Abstract

Metal-catalysed reactions are often hypothesized to proceed on bifunctional active sites, whereby colocalized reactive species facilitate distinct elementary steps in a catalytic cycle^1-8. Bifunctional active sites have been established on homogeneous binuclear organometallic catalysts^9-11. Empirical evidence exists for bifunctional active sites on supported metal catalysts, for example, at metal-oxide support interfaces^2,6,7,12. However, elucidating bifunctional reaction mechanisms on supported metal catalysts is challenging due to the distribution of potential active-site structures, their dynamic reconstruction and required non-mean-field kinetic descriptions^7,12,13. We overcome these limitations by synthesizing supported, atomically dispersed rhodium-tungsten oxide (Rh-WO_x) pair site catalysts. The relative simplicity of the pair site structure and sufficient description by mean-field modelling enable correlation of the experimental kinetics with first principles-based microkinetic simulations. The Rh-WO_x pair sites catalyse ethylene hydroformylation through a bifunctional mechanism involving Rh-assisted WO_x reduction, transfer of ethylene from WO_x to Rh and H₂ dissociation at the Rh-WO_x interface. The pair sites exhibited >95% selectivity at a product formation rate of 0.1 g_propanal cm^-3 h^-1 in gas-phase ethylene hydroformylation. Our results demonstrate that oxide-supported pair sites can enable bifunctional reaction mechanisms with high activity and selectivity for reactions that are performed in industry using homogeneous catalysts.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.