Self- regeneration of Au/CeO2 based catalysts with enhanced activity and ultra-stability for acetylene hydrochlorination

Lin Ye; Xinping Duan; Simson Wu; Tai-Sing Wu; Yuxin Zhao; Alex W Robertson; Hung-Lung Chou; Jianwei Zheng; Tuğçe Ayvalı; Sarah Day; Chiu Tang; Yun-Liang Soo; Youzhu Yuan; Shik Chi Edman Tsang

doi:10.1038/s41467-019-08827-5

Self- regeneration of Au/CeO₂ based catalysts with enhanced activity and ultra-stability for acetylene hydrochlorination

Nat Commun. 2019 Feb 22;10(1):914. doi: 10.1038/s41467-019-08827-5.

Authors

Lin Ye¹, Xinping Duan², Simson Wu¹, Tai-Sing Wu³, Yuxin Zhao², Alex W Robertson⁴, Hung-Lung Chou⁵, Jianwei Zheng¹, Tuğçe Ayvalı¹, Sarah Day⁶, Chiu Tang⁶, Yun-Liang Soo³, Youzhu Yuan⁷, Shik Chi Edman Tsang⁸

Affiliations

¹ Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford, OX1 3QR, UK.
² State Key Laboratory of Physical Chemistry of Solid Surfaces, National Engineering Laboratory for Green Chemical Production of Alcohols-Ethers-Esters, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
³ Department of Physics, National Tsing Hua University, Hsinchu, 30013, Taiwan.
⁴ Department of Materials, University of Oxford, Oxford, OX1 3PH, UK.
⁵ Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, 10617, Taiwan.
⁶ Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
⁷ State Key Laboratory of Physical Chemistry of Solid Surfaces, National Engineering Laboratory for Green Chemical Production of Alcohols-Ethers-Esters, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China. yzyuan@xmu.edu.cn.
⁸ Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford, OX1 3QR, UK. edman.tsang@chem.ox.ac.uk.

Abstract

Replacement of Hg with non-toxic Au based catalysts for industrial hydrochlorination of acetylene to vinyl chloride is urgently required. However Au catalysts suffer from progressive deactivation caused by auto-reduction of Au(I) and Au(III) active sites and irreversible aggregation of Au(0) inactive sites. Here we show from synchrotron X-ray absorption, STEM imaging and DFT modelling that the availability of ceria(110) surface renders Au(0)/Au(I) as active pairs. Thus, Au(0) is directly involved in the catalysis. Owing to the strong mediating properties of Ce(IV)/Ce(III) with one electron complementary redox coupling reactions, the ceria promotion to Au catalysts gives enhanced activity and stability. Total pre-reduction of Au species to inactive Au nanoparticles of Au/CeO₂&AC when placed in a C₂H₂/HCl stream can also rapidly rejuvenate. This is dramatically achieved by re-dispersing the Au particles to Au(0) atoms and oxidising to Au(I) entities, whereas Au/AC does not recover from the deactivation.

Publication types

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