Chloroform Hydrodechlorination over Palladium–Gold Catalysts: A First‐Principles DFT Study

Abstract Hydrodechlorination is a promising method for treating toxic chlorocarbon compounds. Pd is among the most effective catalysts for chloroform hydrodechlorination, and experiments have shown that the Pd–Au alloy catalyst yields superior catalytic performance over pure Pd. Here we examine the chloroform hydrodechlorination mechanism over Pd(1 1 1) and Pd ML /Au(1 1 1) surfaces using periodic, self‐consistent density functional theory calculations (DFT, GGA–PW91) and maximum rate analysis. We suggest that the reaction occurs on both surfaces through complete dechlorination of chloroform followed by hydrogenation of CH* to methane, and that the initial dechlorination step is likely the rate‐limiting step. On Pd(1 1 1), the chloroform dechlorination barrier is 0.24 eV higher than the desorption barrier, whereas on Pd ML /Au(1 1 1), the chloroform dechlorination barrier is 0.07 eV lower than the desorption barrier, which can explain the higher hydrodechlorination activity of the Pd–Au alloy catalyst.