Kinetics of the catalytic hydrochlorination of acetylene on the surface of mechanically preactivated K2PtCl4

The hydrochlorination of acetylene by gaseous HCl is catalyzed at room temperature on the surface of dry K2PtCl4 subjected to mechanical preactivation in an acetylene atmosphere. The acetylene hydrochlorination product is formed by trans addition. The kinetic isotope effect (KIE) upon replacing HCl by DCl is 5 ± 1, which is much greater than the KIE found in the catalytic hydrochlorination of acetylene on the surface of mechanically preactivated K2PtCl6 (1.9). This discrepancy suggests different reaction mechanisms in these two systems.