PtZn alloy - N-doped biocarbon catalyst derived from rice straw for alkali-free glucose oxidation

Selective and efficient oxidation of glucose to sugar acids is a challenge for sustainable chemistry. This study develops catalytic nitrogen-doped biocarbon materials having PtZn bimetallic alloy active sites that promote selective and efficient oxidation of glucose at room temperature without the use of any type of additives. Spectral analyses were used to verify that nitrogen was incorporated into the lattice of the PtZn 1.7 alloy through Zn-N bond coordination. Urea was used as the nitrogen source for preparing PtZn@C-U catalyst that achieved sugar acid yields as high as 95.5% (84.7% gluconic acid, 10.8 % glucaric acid) under atmospheric conditions and ambient temperature (23 °C) in neutral water without alkali. The presence of urea in the synthesis procedure not only promoted biocarbon growth but also generated unsaturated carbon bonds, enhancing the hydrophobicity of the PtZn@C-U. This increase in hydrophobicity led to the exposure of active oxygen sites on the catalyst surface, which functioned as alloy active sites, contributing to the high catalytic performance in aqueous media. The catalyst offers cyclability and stability via N-doping and represents an advance in catalyst design for production of organic acids at ambient conditions.