Effect of calcium ion concentration on the ORR performance of Pd/C catalysts

Noble metal electrocatalysts prepared by microbial methods have attracted extensive attention because of their environmental protection and easy preparation. However, the preparation of electrocatalysts by microbial methods has problems such as large nanoparticles size and low loading rate. In this study, the porous gel co-embedded with Shewanella and alginate is prepared as the adsorption matrix to further enhance its mass transfer and adsorption efficiency. The effect of calcium ion concentration on catalyst performance is explored by optimizing the CaCl₂ concentration to expose more adsorption sites. The results show that when the Ca²⁺ concentration is 0.025 mmol L^-1, the prepared catalyst has the smallest size and the highest Pd loading, and exhibits the best electrochemical activity and stability. This provides a new idea for the preparation of electrocatalysts by microbial methods.