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Hydrogen peroxide production through the electrochemical two-electron oxygen reduction presents a compelling alternative to the anthraquinone process due to the cheap starting materials and low operating temperature and pressure. Transition metal species featuring with multi-active sites, offer high electrochemical activity and selectivity. MXenes, distinguished by excellent electrical conductivity and the two-dimensional structure facilitating smooth ion transportation, further enhance the prospects of this production approach. In this study, three Mo-based MXenes were synthesized: Mo 2 TiC 2 F x , Mo 2 Ti 2 C 3 F x and Mo 2 CF x. Among these, Mo 2 TiC 2 F x emerged as the most promising catalyst for 2e−ORR, achieving a remarkable H 2 O 2 yield of up to 0.54 mol·g cat −1·h−1. Moreover, it also exhibits a high H 2 O 2 selectivity ranging from 81.3 % at 0.2 V to 94.1 % at 0.6 V vs. RHE, coupled with an impressive faradaic efficiency of 76.4 % at 0.4 V using H-cell. Further analysis indicates that the superior 2e−ORR performance can be attributed to the presence of metallic Mo on the surface of Mo 2 TiC 2 F x. [ABSTRACT FROM AUTHOR]

The production of H 2 O 2 by oxygen reduction reaction (ORR) is low energy consumption and environmentally friendly. Pd/C is an effective electrocatalyst for oxygen reduction, while its selectivity is low due to a tendentious four-electron pathway ORR process. The limited reserves of palladium and inevitable corrosion issue of carbon support add extra obstacles toward practical application. In this work, Pd nanoparticles with 3–5 nm were synthesized on MXene sheets. Results indicated that Pd/MXene exhibited 3.5∼4.2 times ring current than Pd/C and much higher H 2 O 2 selectivity. The H 2 O 2 yield of Pd/MXene was measured to be 1.43 mol g−1 h−1. The excellence in electrochemistry was from the synergistic effect of Pd and MXene. The existence of MXene increases metallic Pd on the surface. This study on MXenes as supports of Pd nanoparticles for two-electron oxygen reduction provides extensive reference significance to H 2 O 2 generation. [ABSTRACT FROM AUTHOR]