Self‐catalyzed formation of strongly interconnected multiphase molybdenum‐based composites for efficient hydrogen evolution

Abstract

Molybdenum carbide (MoxC) with variable phase structure possesses flexible hydrogen‐binding energy (HBE), which is a promising hydrogen evolution reaction (HER) catalyst. Herein, a hybrid multiphase MoxC freestanding film coupled with Co3Mo (CM/MoxC@NC) is synthesized through the electrospinning method supplemented by the heteroatom incorporation. CM/MoxC@NC surpasses its pure phase counterparts and exhibits remarkable catalytic activity at 114 mV to deliver a current density of 10 mA cm−2 in acid, which is among the first‐rate level performance reported for MoxC‐based catalysts. The subsequent ex situ and in situ characterizations reveal a phase transition mechanism based on self‐catalysis that CoOx depletes the coordinated C of α‐MoC via the interaction, which realizes the assembly of weak HBE α‐MoC and strong HBE β‐Mo2C, and the enhanced utilization of active materials as well. The multiple structures with optimal HBE are in favor of the stepwise reactions of HER, as the study of the correlation between HBE and phase structure revealed. This study discloses the underlying phase transition mechanism and highlights the HBE–structure relationship that should be considered for catalyst design.

Synergistically boosting the elementary reactions over multiheterogeneous ordered macroporous Mo2C/NC‐Ru for highly efficient alkaline hydrogen evolution

“…18,22,23 However, ΔG H* alone is hardly sufficient to describe the activity of HER in alkaline solutions 26 27,28 In this case, considering the relatively highenergy barrier for water dissociation of Ru, 26 a well-designed substrate with good water dissociation ability is essential to achieving efficient electrocatalysis for alkaline HER. Previous work has confirmed that Mo 2 C possesses a low water dissociation energy in alkali, 29,30 and thus a carbon-Mo 2 C composite support may be a good choice for Ru anchoring.…”

Ethanol‐Induced Hydrogen Insertion in Ultrafine IrPdH Boosts pH‐Universal Hydrogen Evolution

“…[1][2][3][4][5] Electrocatalytic water splitting via the hydrogen evolution reaction (HER) is a viable high-purity hydrogen generation technology with widely accessible reactants, competitive cost-effectiveness, and stable output that aroused intense research in contrast to the traditional natural gas decomposition and watergas conversion. [6][7][8][9][10] Platinum (Pt)-based materials are remaining utilized as the most desirable HER catalysts but are largely limited by the prohibitive costs and scarce reserves. [11][12][13][14][15][16] Palladium (Pd) with a similar electronic structure to Pt has been a promising Pt-free alternative with a much richer reservation.…”

Co-doped Ni–Mo oxides: highly efficient and robust electrocatalysts for urea electrooxidation assisted hydrogen production

“…Urea electrooxidation received great attention among the above organics due to its advantages as non-toxic, rich source, and thermodynamic feasibility at low potential. [18][19][20][21][22] However, the complex sixelectron reaction of UOR inherently has sluggish kinetics, 23 which require catalysts to accelerate the reaction rate. 24 Nibased catalysts [24][25][26][27][28] have been widely reported in UOR because Ni metal sites can efficiently decompose urea into NH 3 and CO 2 .…”