Hydrogen peroxide (H2O2) oxidation and reduction reactions (HPOR/HPRR) are pivotal in various innovative electrochemical energy conversion devices. A comprehensive understanding of these mechanisms is critical for catalyst design and performance improvement in these applications. In this work, we systematically investigate the HPOR/HPRR mechanisms on low-index Pt surfaces, specifically Pt(111), Pt(100) and Pt(110), through density functional theory (DFT) calculations combined with the computational hydrogen electrode (CHE) model. For HPOR, all the low-index Pt surfaces exhibit a unified potential-determining step (PDS) involving the electrochemical oxidation of hydroperoxyl intermediates (HOO*). The binding free energy of HOO* (ΔGHOO*) emerges as an activity descriptor, with Pt(110) exhibiting the highest HPOR activity. The HPRR mechanism follows a chem-electrochemical (C-EC) pathway. The rate-determining step (RDS) of HPRR is either the cleavage of the HO–OH bond (chemical) or the reduction of HO (electrochemical), depending on their respective activation energies. These activation energies are functions of the HO* binding free energy, ΔGHO*, establishing ΔGHO* as the descriptor for HPRR activity prediction. Pt(111) and Pt(100) are identified as the most active HPRR catalysts among the studied metal surfaces, although they still experience a significant overpotential. The scaling relationship between ΔGHOO* and ΔGHO* reveals a thermodynamic coupling of HPOR and HPRR, explaining their occurrence on Pt surfaces. These findings provide important insights and activity descriptors for both HPOR and HPRR, providing valuable guidance for the design of electrocatalysts in H2O2-related energy applications and fuel cells.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |