Palladium-halloysite nanocomposites as an efficient heterogeneous catalyst for acetylene hydrochlorination

Abstract

Halloysite nanotubes (HNTs) were employed to design and synthesize palladium-based heterogeneous catalysts with the purpose of exploring an efficient non-mercuric catalyst for acetylene hydrochlorination. Various Pd/UHNTs catalysts with urea modification were prepared using ultrasonic-assisted impregnation method and the Pd/9UHNTs catalyst exhibited the best catalytic performance, with 90% acetylene conversion and above 94% vinyl chloride selectivity under the reaction conditions of T = 160 °C, a C2H2 gas hourly space velocity (GHSV) = 150 h−1 and V(HCl): V(C2H2) = 1.25. The results demonstrated that the urea additive (mainly nitrogen species) significantly immobilized Pd species and inhibited the carbon deposition on the catalyst surface, thus contributing to enhance the catalytic performance of Pd/HNTs catalysts during the reaction.

Keywords

• Halloysite nanotubes
• Pd catalysis
• Urea
• Acetylene hydrochlorination