Mesoporous Carbon Hollow Spheres as Efficient Electrocatalysts for Oxygen Reduction to Hydrogen Peroxide in Neutral Electrolytes
Yongyu Pang, Ke Wang, Huan Xie, Yuan Sun, Maria‐Magdalena Titirici, Guoliang Chai
Abstract
Hydrogen peroxide is a widely used and important chemical in industry. A two-electron electrochemical oxygen reduction reaction (2e– ORR) is a clean and on-site method for H2O2 production. Here, we report metal-free catalysts (mesoporous carbon hollow spheres, MCHS) for high-efficiency H2O2 production in neutral electrolytes (0.1 M PBS). The selectivity of H2O2 on MCHS catalysts is higher than 90% at a wide range of potentials (0.35–0.62 V), and it can reach 99.9% at a potential of 0.57 V. These catalysts show some of the best performances for H2O2 production in neutral electrolytes. It is preferable to develop H2O2 catalysts in a neutral environment, as the pH of the stabilizers used for H2O2 is also close to neutral. The outstanding activity of our catalyst comes from a combination of factors such as suitable porosity, the content of oxygen functional groups, and the types of different species of oxygen functional groups. First-principles simulations show that a catalyst with suitable mixed oxygen and COOH functional groups plays an important role in the catalytic formation of H2O2. The reported metal-free catalysts are promising catalysts for high-efficiency production of H2O2 in the future.