Three-dimensional PdCuM (M = Ru, Rh, Ir) Trimetallic Alloy Nanosheets for Enhancing Methanol Oxidation Electrocatalysis

Abstract

Owing to their intrinsically high activity and rich active sites on the surface, noble metal materials with an ultrathin two-dimensional nanosheet structure are emerging as ideal catalysts for boosting fuel cell reactions. However, the realization of controllable synthesis of multimetallic Pd-based alloy ultrathin nanosheets (NSs) for achieving enhanced electrocatalysis evolved from compositional and structural advantages remains a grand challenge. Herein, we report a universal method for the construction of a new series of the three-dimensional (3D) multimetallic PdCuM (M = Ru, Rh, Ir) superstructures that consist of ultrathin alloy NSs. Different from the conventional 2D ultrathin nanostructure, the 3D PdCuM NSs that endowed with abundant routes for fast mass transport, high noble material utilization efficiency, and ligand effect from M to PdCu display large promotion in electrocatalytic performance for the methanol oxidation reaction. Impressively, the composition-optimized Pd 59 Cu 33 Ru 8 NSs, Pd 57 Cu 34 Rh 9 NSs, and Pd 63 Cu 29 Ir 8 NSs show the mass activities of 1660.8, 1184.4, and 1554.8 mA mg −1 in alkaline media, which are 4.9, 3.5, and 4.6-fold larger than that of commercial Pd/C, respectively. More importantly, all of the PdCuM NSs are also very stable for long-term electrochemical tests.

Ultrafine Pt‐Based Nanowires for Advanced Catalysis

“…[55][56][57] Generally, active site engineering involves two key elements: the intrinsic activity and number of active sites. [58][59][60] Regarding the former, enhancing the intrinsic activity of active sites is highly imperative as the catalytic performance is restricted when loading catalysts that are approaching the limits. Generally, catalyst with rough surface is typically more favorable for enhancing catalytic performance compared with catalyst with smooth surfaces owing to the relatively larger number of active sites and strong electronic effect.…”

Low‐Dimensional Metallic Nanomaterials for Advanced Electrocatalysis

“…In addition to using superstructure for OER, Jin et al demonstrated the construction of a series of PdCuM ((M = Ru, Rh, Ir) superstructure that assembled by nanosheets based on organic ligand-assisted growth method, which displayed both high electroactivity and durability toward methanol oxidation reactions (MORs). [54] The enhanced electrocatalytic performance could be ascribed to their structural characteristics, including abundant accessible sites, ultrathin nanosheets, and largely exposed surface areas (Figure 3c-e). More importantly, the nanosheets assembled 3D nanostructures endowed the catalyst with excellent electrochemical stability and mechanical toughness.…”

Platinum‐Based Electrocatalysts for Direct Alcohol Fuel Cells: Enhanced Performances toward Alcohol Oxidation Reactions

“…demonstrated that the support can also directly alter the atomic structure of electrocatalysts. [148] The lattice mismatch between the 2-3 atomic Pt layers and intermetallic Pt 3 Ga support produces a 3.2 % tensile strain along the [001] direction while the tensile strain along other two directions ( [100] and [010]) is negligible. These tensile-strained electrocatalysts possess significantly greater activity for MOR compared with commercial Pt/C and unstrained Pt nanocrystals (Figure 7c).…”

“…A modulated electronic structure is necessary for a high‐active catalyst because it is favourable for lowing the adsorption energy of the reactants adsorbed on the catalyst surface. For metal electrocatalysts, one of the most effective strategies to modify their electronic structure is to introduce the second or more metal elements into Pt matrix to form bimetallic or multi‐metallic nanocrystals [46,99–103] . The d‐band centre of Pt will be shifted because the mismatch arrangement of atoms in Pt‐based bimetallic or multi‐metallic catalysts results in lattice strain, including tensile strain and compressive stress.…”