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Boron and Nitrogen Co-doped Molybdenum Carbide Nanostructures for Oxygen Reduction Electrocatalysis
ACS Applied Nano Materials ( IF 5.9 ) Pub Date : 2021-08-23 , DOI: 10.1021/acsanm.1c01550
Caimei He 1 , Yezheng Cai 1, 2 , Zhaoling Ma 1, 2 , Xinxian Zhong 1 , Hongqiang Wang 1, 2 , Qingyu Li 1, 2 , Youguo Huang 1, 2
Affiliation  

Molybdenum carbide (Mo2C) with unique Pt-like electronic structure displays promising electrocatalysis for oxygen reduction reaction (ORR). However, the oxygen adsorption of Mo2C is overly strong for boosted catalytic activity. Herein, this work developed a bidirectional electronegative heteroatom doping strategy to tune the electronic cloud density of Mo2C. Boron and nitrogen, which have different electronegativities compared to Mo, co-doped nano-Mo2C moieties embedded in a nanoporous nitrogen-doped carbon frame (B,N-Mo2C/NPNC) were synthesized via a cross-linking–pyrolysis process. The introduced B not only tailored the electronic structure of Mo2C but also created additional electron-deficient B active sites for ORR. Additionally, the unique nanoporous carbon structure with dominant nanochannels benefits the exposure of specific surface areas and fast mass transfer. As a result, compared to N-Mo2C/NPNC without B tuning, B,N-Mo2C/NPNC exhibited superior ORR catalytic activity comparable to commercial Pt/C catalysts, making it outstanding among the Mo-based ORR catalysts. Moreover, B,N-Mo2C/NPNC showed robust catalytic stability for ORR with little shift in half-wave potential even after 10,000 cycles. As a cathode catalyst, a B,N-Mo2C/NPNC-driven zinc-air battery displayed discharge performance superior to the Pt/C-driven one, heralding promising application prospects. This work provided a feasible strategy for boosting the ORR catalytic activity of molybdenum carbide by simultaneously tuning the electronic structure, creating auxiliary active site, and constructing three-dimensional opening nanoporous carbon structures, which can be extended to other metal catalysts for energy conversion.

中文翻译:

用于氧还原电催化的硼和氮共掺杂碳化钼纳米结构

具有独特的类铂电子结构的碳化钼 (Mo 2 C) 显示出有希望的氧还原反应 (ORR) 电催化。然而,Mo 2 C的氧吸附对于提高的催化活性而言过强。在此,这项工作开发了一种双向电负性杂原子掺杂策略来调节 Mo 2 C的电子云密度。硼和氮与 Mo 相比具有不同的电负性,共掺杂纳米 Mo 2 C 部分嵌入纳米多孔氮掺杂碳框架(B,N-Mo 2 C/NPNC)是通过交联-热解过程合成的。引入的B不仅定制了Mo 2的电子结构C 但也为 ORR 创造了额外的缺电子 B 活性位点。此外,具有主导纳米通道的独特纳米多孔碳结构有利于特定表面积的暴露和快速传质。因此,与没有 B 调谐的N-Mo 2 C/NPNC相比,B,N-Mo 2 C/NPNC 表现出与商业 Pt/C 催化剂相当的优异 ORR 催化活性,使其在 Mo 基 ORR 催化剂中脱颖而出。此外,B,N-Mo 2 C/NPNC 对 ORR 显示出强大的催化稳定性,即使在 10,000 次循环后,半波电位变化也很小。作为阴极催化剂,B,N-Mo 2C/NPNC 驱动的锌空气电池显示出优于 Pt/C 驱动的锌空气电池的放电性能,预示着广阔的应用前景。该工作通过同时调整电子结构、创建辅助活性位点和构建三维开口纳米多孔碳结构,为提高碳化钼的 ORR 催化活性提供了一种可行的策略,该结构可以扩展到其他金属催化剂进行能量转换。
更新日期:2021-09-24
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