Kim, Seongbeen Choi, Changhyeok Hwang, Jongkook Park, Jinkyu Jeong, Jooyoung Jun, Hyunwoo Lee, Seonggyu Kim, Soo-Kil Jang, Jong Hyun Jung, Yousung Lee, Jinwoo 2024-01-19T17:34:05Z 2024-01-19T17:34:05Z 2021-09-05 2020-04-28 1936-0851 https://pubs.kist.re.kr/handle/201004/118708 To overcome inherent limitations of molybdenum carbide (MoxC) for hydrogen evolution reaction (HER), i.e., low density of active site and nonideal hydrogen binding strength, we report the synthesis of valence-controlled mesoporous MoxC as a highly efficient HER electrocatalyst. The synthesis procedure uses an interaction mediator (IM), which significantly increases the density of active site by mediating interaction between PEO-b-PS template and Mo source. The valence state of Mo is tuned by systematic control of the environment around Mo by controlled heat treatment under air before thermal treatment at 1100 degrees C. Theoretical calculations reveal that the hydrogen binding is strongly influenced by Mo valence. Consequently, MoxC achieves a significant increase in HER activity (exceeding that of Pt/C at high current density similar to 35 mA/cm(2) in alkaline solution). In addition, a volcano-type correlation between HER activity and Mo valence is identified with various experimental indicators. The present strategies can be applied to various carbide and Mo-based catalysts, and the established Mo valence and HER relations can guide development of highly active HER electrocatalysts. English AMER CHEMICAL SOC TUNGSTEN CARBIDE OXYGEN REDUCTION RATIONAL DESIGN CATALYSTS ELECTROCATALYSTS CARBON NANOPARTICLES WATER PHOSPHIDE NANOWIRE Interaction Mediator Assisted Synthesis of Mesoporous Molybdenum Carbide: Mo-Valence State Adjustment for Optimizing Hydrogen Evolution Article 10.1021/acsnano.0c01285 1 ACS NANO, v.14, no.4, pp.4988 - 4999 ACS NANO 14 4 4988 4999 scie scopus 000529895500114 2-s2.0-85084167437 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Chemistry Science & Technology - Other Topics Materials Science Article TUNGSTEN CARBIDE OXYGEN REDUCTION RATIONAL DESIGN CATALYSTS ELECTROCATALYSTS CARBON NANOPARTICLES WATER PHOSPHIDE NANOWIRE electrochemical hydrogen evolution reaction molybdenum carbide mesoporous material metal valence volcano correlation