An Efficient AuRb/AC Catalyst for Industrial Vinyl Chloride Monomer Production

Gold catalysts are considered the most promising non-mercury alternatives for the environmentally urgent replacement of toxic mercuric chloride (HgCl2/AC) catalysts in the industrial production of vinyl chloride monomer (VCM) via acetylene hydrochlorination. Their commercialization, however, is critically limited by rapid deactivation due to the reduction and agglomeration of active Au+ species. To develop a practical catalyst with industrial viability, we designed and synthesized a rubidium-promoted gold catalyst supported on activated carbon (AuRb/AC). This catalyst demonstrates exceptional and stable performance, achieving a C2H2 conversion of 88.3% with a VCM selectivity exceeding 99.9%, which is both superior to the conventional Au/AC catalyst and approaches the level required for industrial application. Most notably, the AuRb/AC catalyst shows outstanding operational stability, maintaining its initial activity without noticeable deactivation during a 110 h time-on-stream test (500 h–1), a key metric for process economics. Characterization reveals that the introduced Rb effectively stabilizes the active Au+ centers against reduction and sintering, while also promoting reactant activation. This work provides a robust and efficient catalytic solution, paving the way for the practical, industrial application of gold-based catalysts in acetylene hydrochlorination.