Constructing the single-site of pyridine-based organic compounds for acetylene hydrochlorination: From theory to experiment

Acetylene hydrochlorination reaction requires toxic mercuric chloride catalyst, which caused serious environmental pollution by mercury in recent years. Though Au-based catalysts show the best catalytic activity and high rates of acetylene conversion, much work still needs to be done to reduce the cost before their large-scale applications. Here, a pure pyridine-based organic polymer was successfully designed and assembled, which contains only one nitrogen species and exhibits a high activity with acetylene conversion reaching 88% and the selectivity of vinyl chloride above 99%. Both experimental and density functional theory (DFT) studies directly demonstrate that the pyridinic N atom in pyridine ring is the active site of the catalyst and the insertion of acetylene to HCl might be the rate-determining step. Different from traditional carbonization and aminating treatment at high temperature, the pyridine-based polymers were obtained by polymerization in liquid phase. Besides, the activity of the catalyst may be determined by these combined effects of surface area, pores structure, and the amount of pyridinic N.

Automated summary

A pure pyridine-based organic polymer catalyst with high catalytic activity in acetylene hydrochlorination reaction has been successfully designed and assembled. It demonstrates a high acetylene conversion rate of 88% and a vinyl chloride selectivity of over 99%. The active site of the catalyst is identified as the pyridinic N atom in the pyridine ring, with acetylene insertion to HCl potentially being the rate-determining step.