1成果简介 

        过氧化氢（H2O2）是重要的化工产品，传统蒽醌法能耗高、污染大，两电子氧还原反应（2e-ORR）电合成H2O2是可持续替代方案。近期，北京化工大学陈咏梅、深圳大学蒋皓珉博士在《Fuel》期刊发表题为“Metallic bismuth-embedded mesoporous carbon hollow spheres for highly selective electrocatalytic hydrogen peroxide production via two-electron oxygen reduction” 的论文，首次通过配体辅助限域策略，将金属铋纳米颗粒均匀嵌入介孔碳空心球（Bi@MCHS），构建出高性能 2e-ORR 电催化剂。该催化剂兼具高选择性、高活性、高稳定性，在碱性条件下H2O2选择性最高达97.5%，流动电解池中H2O2产率达30.8 μmol cm-2 min-1，为绿色高效电合成H2O2 提供全新电催化材料设计见解。

        2图文导读  

        Fig. 1. Schematic illustration of Bi@MCHS preparation.

        Fig. 2. Characterizations of Bi@MCHS. (a) SEM image; (b) TEM image; (c) the dark-ffeld TEM image and elemental distribution mapping; (d) Distribution and particle size statistics of metallic bismuth particles in dark-ffeld images; (e) XRD patterns of Bi@MCHS and comparison samples; (f) the N2 adsorption-desorption isotherm and the average pore size plot (inset image).

        Fig. 3. 2e-ORR performance and electrolytic performance of Bi@MCHS. (a) RRDE polarization curves recorded in O2-saturated 0.1 M KOH at a scan rate of 5 mV s-1 and a rotation rate of 1600 rpm. (b) H2O2selectivity. (c) the electron transfer number calculated from the polarization curves. (d) Comparison on H2O2 selectivity and ring current of different catalysts obtained from the I-t tests at 0.5 V. (e) Variation of the inverse of the current density with the inverse of the square root of the rotational speed for Koutechy-Levich analysis for Bi@MCHS. (f) Kinetic current density curves of Bi@MCHS and reported catalysts. (g) The stability test of Bi@MCHS conducted with a fixed disk potential of 0.5 V.

        Fig. 4. (a) LSV curves of Bi@MCHS with different bismuth addition amounts. (b) Comparison of Bi content and hydrogen peroxide selectivity at 0.5 V with different bismuth addition amounts. (c) Calculated volcano plot for 2e-ORR related electroreduction of oxygen to H2O2. (d) Calculated free energy diagrams for 2e-ORR on the Bi site in metallic Bi, the C site in graphene, and C site in metallic Bi-graphene. Optimized structures of *OOH on the surface of graphene (e) and metallic Bi-graphene (f). (g) Optimized structure differential charge densities of adsorbed *OOH on metallic Bi surface.

        3小结 

        本研究开发配体辅助限域策略，成功合成金属铋嵌入介孔碳空心球（Bi@MCHS）电催化剂。金属铋作为活性中心，提供最优* OOH吸附能，实现超高 2e-ORR 选择性；中空介孔碳球结构大幅提升比表面积与传质效率，暴露更多活性位点。该催化剂在碱性体系中表现出优异的活性、选择性与稳定性，流动电解池可连续高效制备H2O2。这项工作建立“活性位点设计 + 介观结构调控”的协同催化理念，为高性能2e-ORR催化剂开发与绿色电合成H2O2工业化提供重要参考。

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