In Situ Replacement Synthesis of Co@NCNT Encapsulated CoPt₃@Co₂P Heterojunction Boosting Methanol Oxidation and Hydrogen Evolution

Abstract

Simultaneous boosting electrochemical methanol oxidation reaction (MOR) for direct methanol fuel cells and production of hydrogen is meaningful but challenging. Herein, a sea urchin‐shaped cobalt‐embedded N‐doped carbon nanotubes (Co@NCNT) encapsulated CoPt3@Co2P heterojunction (CoPt3@Co2P/Co@NCNT) is fabricated. Theoretical calculations confirm that electrons at the interfaces transfer from CoPt3 to Co2P, where electron hole region on CoPt3 is beneficial to improving the MOR activity, whereas accumulation region on Co2P favors to the optimization of H2O and H* absorption energies for hydrogen evolution reaction (HER). Benefitting from its interfacial electronic reconfiguration, the CoPt3@Co2P/Co@NCNT heterojunction exhibits excellent electrocatalytic performances for MOR and HER, in which the mass activity (2981 mA mgPt−1) for MOR is 14.2 times than that of Pt/C (20%), and the smallest overpotentials only requires 19 mV to deliver a current density of 10 mA cm−2 for HER. Moreover, the electrolyzer employing CoPt3@Co2P/Co@NCNT for anodic MOR and cathodic H2 production only requires a low voltage of 1.43 V at 10 mA cm−2 with impressive long‐life cycling stability, which is obviously better than that of commercial Pt/C//RuO2. This study offers a novel strategy for other organics oxidation reaction coupled with HER catalyzed production of hydrogen.

Ni2P–Co2P Nanowire Arrays on Nickel Foam as a Robust pH-Universal Electrocatalyst for High-Efficiency Hydrogen Evolution Reaction

“…The Co 0 may be from the reduction of Co oxides by PH 3 during the phosphating process. Meanwhile, the binding energy of Co 2+ in Ni 2 P–Co 2 P is 783.4 eV, which positively shifted by about 0.4 eV compared with that in Co 2 P (783.8 eV). − We calculated the relative content of Co 3+ and Co 2+ using XPS. In Co 2 P, Co 3+ :Co 2+ = 55:45, and in Ni 2 P–Co 2 P, Co 3+ :Co 2+ = 62:38, which indicates that the content of Co 3+ has increased in Ni 2 P–Co 2 P. All of the above findings show that electrons are transferred away from Co.…”

Regulation of the shell thickness and shell components in PtCu/PdCu core–shell tripods for ethylene glycol and glycerol oxidation reactions

“…Meanwhile, the total density of states of PtCu/PdCu is higher than that of PtCu, indicating that PtCu/PdCu has good electrical conductivity during the EGOR, thus favouring electron transfer. 42 To further investigate the source of activity of the PtCu/PdCu core–shell structure, we calculated its charge density difference. Fig.…”

Designing a Built-In Electric Field for Efficient Energy Electrocatalysis

“…Apart from OER, the HER process is also important for water splitting . Therefore, exploiting efficient and durable bifunctional electrocatalysts to reduce energy consumption toward HER and OER processes is urgent. , However, it is limited by the incompatibility between HER and OER catalytic sites.…”

“…Apart from OER, the HER process is also important for water splitting. 116 Therefore, exploiting efficient and durable bifunctional electrocatalysts to reduce energy consumption toward HER and OER processes is urgent. 117,118 However, it is limited by the incompatibility between HER and OER catalytic Li−S batteries employing metal Li and sulfur as electrode active materials are promising candidates for next-generation energy storage systems due to the high theoretical capacity (1675 mA h g −1 ) and extraordinary energy density (2600 W h kg −1 ).…”