Electrocatalytic hydrogenation of phenol by active sites on Pt-decorated shrimp shell biochar catalysts: Performance and internal mechanism

• The Pt-decorated shrimp shell biochar was applied as cathode catalyst. • The Pt/SSB catalysts achieved efficient and selective conversion of phenol. • The C C and C O bonds in precursor were reduced by [H] to produce cyclohexanol. • The C O, Pt, and Pt-N x sites dominated in phenol conversion. The development of highly-active electrocatalysts and identification of active sites contribution are necessary for electrocatalytic hydrogenation (ECH) of bio-oil. Herein, the Pt-decorated shrimp shell biochar (SSB) catalysts with high nitrogen content was prepared successfully. The biochar-based catalysts were first used for the ECH of bio-oil model compounds. Results showed that the Pt/SSB catalysts exhibited excellent electrocatalytic activity and stability, realizing 100 % conversion of phenol and 98 % total selectivity of cyclohexanone and cyclohexanol within 5 h. By correlation analysis and density functional theory (DFT) calculations, the Pt, Pt-N x , and C O sites in Pt/SSB catalysts were found to play an important role in the stepwise hydrogenation of phenol. Furthermore, the Pt-N x sites were identified as the main contributor to the high selectivity of cyclohexanol generation. This study lays the foundation for the controllable preparation of electrocatalysts with high activity and stability, which is significant for large-scale upgrading of bio-oil in the future.