Pd-TiO2 Schottky heterojunction catalyst boost the electrocatalytic hydrodechlorination reaction

Abstract Electrocatalytic hydrodechlorination (EHDC) provides one promising solution to mitigate challenges from the water pollutions by persistent chlorinated organics. Palladium (Pd) has shown appealing properties as EHDC catalysts, while the low earth abundance has urged us to raise its activity and minimize usage. Herein, one novel semiconductor-metal Pd-TiO2 Schottky heterojunction catalyst was developed, which notably outperformed the conventional Pd-C catalyst in mass activity, dechlorination degree and energy selectivity towards EHDC of 2,4-dichlorophenol (2,4-DCP) in water. A combined experimental and DFT calculation study on mechanism revealed that the primary product phenol had a considerable negative effect on EHDC by competing the active sites with 2,4-DCP. The enhanced performance of Pd-TiO2 originated from the Schottky heterojunction-induced metal-support interactions, which optimized the Pd electronic structure and balanced the 2,4-DCP adsorption and phenol desorption on Pd. This study highlights one novel strategy to boost the metal performance in electrocatalytic hydrogenation reactions.