Boron Nitride-Confined Nanographene as a Metal-Free Catalyst for Acetylene Hydrochlorination

Substitution of toxic mercury catalysts for the manufacture of vinyl chloride monomer (VCM) via acetylene hydrochlorination is a global initiative. We report herein boron nitride matrix-confined nanographene (BNC) as a metal-free catalyst, which is characterized by abundant B-N-C active sites at the interconnected nanographene-boron nitride domains. Their unique electronic structure facilitates the adsorption and polarization of linear acetylene molecules, as evidenced by microscopic elemental analysis and spectroscopic characterization, as well as theoretical calculations. Acetylene conversion increases almost linearly with the content of B-N-C sites. An optimized catalyst enables almost complete conversion of acetylene and 99% VCM selectivity, and it delivers stable performance within an 800 h test at 260 °C and 45 h^-1. Notably, even at an elevated space velocity up to 230 h^-1, acetylene conversion and VCM selectivity still reach 99%. It outperforms conventional nitrogen-doped carbon and boron nitride catalysts. This BNC catalyst shows great potential for the sustainable production of vinyl chloride.