电合成高浓度中性过氧化氢的羧基化六方氮化硼/石墨烯构型

南京工业大学王军团队报道了电合成高浓度中性过氧化氢的羧基化六方氮化硼/石墨烯构型。相关研究成果于2023年12月29日发表在《德国应用化学》。

通过双电子（2e-）氧（O₂）还原反应（ORR）电合成过氧化氢（H₂O₂）在取代传统能源密集型蒽醌工艺方面具有巨大潜力，但低成本、高活性和选择性催化剂的设计对于在工业相关电流密度下长期生产H₂O₂具有很大的挑战性，尤其是在中性电解质下。

为了解决这个问题，研究人员通过B,N共掺杂与表面氧基团功能化的耦合，在商业活性炭上构建了羧化六方氮化硼/石墨烯（h-BN/G）异质结。最优催化剂具有高的2e-ORR选择性（>95%）、产率（高达13.4 mol g^-1 h^-1）和法拉第效率（FE，>95%）。在100mA cm^-2的高电流密度下长期产生H₂O₂导致累积浓度高达2.1 wt.%。

原位拉曼光谱和理论计算的结合表明，羧化的h-BN/G构型促进了O₂的吸附和关键中间体（OOH*和HOOH*）的稳定，能够使低能量势垒用于活性位点释放HOOH*的速率决定步骤，从而提高2e-ORR性能。利用这种电化学合成的H₂O₂快速降解染料，进一步说明了其有前景的实际应用。

附：英文原文

Title: Carboxylated Hexagonal Boron Nitride/Graphene Configuration for Electrosynthesis of High-Concentration Neutral Hydrogen Peroxide

Author: Zhixin Song, Xiao Chi, Shu Dong, Biao Meng, Xiaojiang Yu, Xiaoling Liu, Yu Zhou, Jun Wang

Issue&Volume: 2023-12-29

Abstract: The electrosynthesis of hydrogen peroxide (H2O2) via two-electron (2e-) oxygen (O2) reduction reaction (ORR) has great potential to replace the traditional energy-intensive anthraquinone process, but the design of low-cost and highly active and selective catalysts is greatly challenging for the long-term H2O2 production under industrial relevant current density, especially under neutral electrolytes. To address this issue, this work constructed a carboxylated hexagonal boron nitride/graphene (h-BN/G) heterojunction on the commercial activated carbon through the coupling of B, N co-doping with surface oxygen groups functionalization. The champion catalyst exhibited a high 2e- ORR selectivity (>95%), production rate (up to 13.4 mol g-1 h-1), and Faradaic efficiency (FE, >95%). The long-term H2O2 production under the high current density of 100 mA cm-2 caused the cumulative concentration as high as 2.1 wt.%. The combination of in-situ Raman spectra and theoretical calculation indicated that the carboxylated h-BN/G configuration promotes the adsorption of O2 and the stabilization of the key intermediates (OOH* and HOOH*), allowing a low energy barrier for the rate-determining step of HOOH* release from the active site, and thus improving the 2e- ORR performance. The fast dye degradation by using this electrochemical synthesized H2O2 further illustrated the promising practical application.

DOI: 10.1002/anie.202317267

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202317267