Construction of an extraordinary stable mesoporous carbocatalyst in acetylene hydrochlorination via boric acid assistance

In recent years, metal-free carbon catalysts have garnered significant attention as substitutes for metal catalysts due to their cost-effectiveness and increased resistance to poisoning. However, the stability of metal-free carbon catalysts still lags behind that of metal catalysts, presenting a significant hurdle to industrialization. To enhance the catalytic stability of these catalysts, a boron-nitrogen co-doped mesoporous carbon (B, N-MC) catalyst was synthesized using polyacrylonitrile (PAN) as the carbon and nitrogen source, with boric acid serving as the electron regulator. The acetylene conversion on the B, N-MC(0.5) catalyst reached 62.8% at 220 °C and gas hourly space velocity (GHSV) of C2H2 at 300 h-1, even high than 0.25%Au/AC catalyst (53.3 %). Importantly, the B, N-MC(0.5) catalyst exhibited excellent stability, maintaining its initial activity even after 500 hours of evaluation. Experimental and theoretical analyses demonstrate that the B-N pairs, facilitated by the electronic regulation ability of boric acid, effectively inhibits the polymerization of acetylene molecules, mitigates the formation of carbon deposits, thereby enhancing the stability of the catalyst.