Effects of Sb2o3 Polymorphism on the Performances for Electrocatalytic H2o2 Production Via the Two-Electron Water Oxidation Reaction

Electrochemical preparation of hydrogen peroxide (H 2 O 2 ) via the two-electron water oxidation reaction (2e − WOR) is a promising method. As a potential electrocatalyst for the 2e − WOR, antimony oxide (Sb 2 O 3 ) exists in two different crystal systems, cubic and orthorhombic phases. The arrangements of surface atom structures of these two polymorphs are diverse, which would theoretically lead to different selectivity for the 2e − WOR. The cubic and orthorhombic Sb 2 O 3 are synthesized in this work and their performances for H 2 O 2 generation are systematically measured and compared. Our results show that the cubic Sb 2 O 3 exhibits improved Faradic efficiency and production rate of H 2 O 2 than the orthorhombic one. Density functional theory calculations suggest that the main characteristic facet of the cubic Sb 2 O 3 is thermodynamically more favorable for the 2e − WOR than that of the orthorhombic Sb 2 O 3 .