Preparation and Synergy of Supported Ru<sup>0</sup> and Pd<sup>0</sup> for Rapid Chlorate Reduction at pH 7
Jinyu Gao, Shaohua Xie, Fudong Liu, Jinyong Liu
Abstract
High Resolution Image Download MS PowerPoint Slide Chlorate (ClO 3 – ) is a common water pollutant due to its gigantic scale of production, wide applications in agriculture and industry, and formation as a toxic byproduct in various water treatment processes. This work reports on the facile preparation, mechanistic elucidation, and kinetic evaluation of a bimetallic catalyst for highly active ClO 3 – reduction into Cl – . Under 1 atm H 2 and 20 °C, Pd II and Ru III were sequentially adsorbed and reduced on a powdered activated carbon support, affording Ru 0 –Pd 0 /C from scratch within only 20 min. The Pd 0 particles significantly accelerated the reductive immobilization of Ru III as >55% dispersed Ru 0 outside Pd 0 . At pH 7, Ru–Pd/C shows a substantially higher activity of ClO 3 – reduction (initial turnover frequency >13.9 min –1 on Ru 0; rate constant at 4050 L h –1 g metal –1 ) than reported catalysts (e.g., Rh/C, Ir/C, Mo–Pd/C) and the monometallic Ru/C. In particular, Ru–Pd/C accomplished the reduction of concentrated 100 mM ClO 3 – (turnover number > 11,970), whereas Ru/C was quickly deactivated. In the bimetallic synergy, Ru 0 rapidly reduces ClO 3 – while Pd 0 scavenges the Ru-passivating ClO 2 – and restores Ru 0 . This work demonstrates a simple and effective design for heterogeneous catalysts tailored for emerging water treatment needs.