Tunable intrinsic strain in two-dimensional transition metal electrocatalysts

Abstract

Tuning surface strain is a powerful strategy for tailoring the reactivity of metal catalysts. Traditionally, surface strain is imposed by external stress from a heterogeneous substrate, but the effect is often obscured by interfacial reconstructions and nanocatalyst geometries. Here, we report on a strategy to resolve these problems by exploiting intrinsic surface stresses in two-dimensional transition metal nanosheets. Density functional theory calculations indicate that attractive interactions between surface atoms lead to tensile surface stresses that exert a pressure on the order of 105atmospheres on the surface atoms and impart up to 10% compressive strain, with the exact magnitude inversely proportional to the nanosheet thickness. Atomic-level control of thickness thus enables generation and fine-tuning of intrinsic strain to optimize catalytic reactivity, which was confirmed experimentally on Pd(110) nanosheets for the oxygen reduction and hydrogen evolution reactions, with activity enhancements that were more than an order of magnitude greater than those of their nanoparticle counterparts.

Intermetallic Compounds as an Alternative to Single‐atom Alloy Catalysts: Geometric and Electronic Structures from Advanced X‐ray Spectroscopies and Computational Studies

“…The size of the particles will further influence the strain exerted across the particle, which may further affect the d electronic states. This strain effect is well‐discussed in literature for alloy films . Despite the quantitative differences, the relative accuracy of the predicted shifts replicates the correct trend in electron energies, even for compositional changes of the same alloying metal.…”

Fine‐Tuning Intrinsic Strain in Penta‐Twinned Pt–Cu–Mn Nanoframes Boosts Oxygen Reduction Catalysis

“…As is well known, the ultrathin structure in metallic nanocrystals facilitates the generation of compressive strain, which could effectively tune the electronic structure of metal for the optimized catalytic property . Impressively, the Pt–Cu–Mn UNFs possess ultrathin structure as compared to Pt–Cu–Mn PNFs.…”

“…In recent studies, tuning surface strain has become one of the most powerful strategy to boost the electrocatalytic properties of Pt‐based catalysts . It could modulate the surface electronic structure to an appropriate condition for energetics of reaction intermediates, resulting in the enhancement of catalytic performance . Previous reports have demonstrated that tuning the surface strain of Pt‐based catalysts could dramatically improve the catalytic activity for ORR due to the optimal oxygen adsorption energy and 1% compressive strain could increase the catalytic activity of Pt catalyst by more than 300% .…”

Atomically Dispersed Semimetallic Selenium on Porous Carbon Membrane as an Electrode for Hydrazine Fuel Cells

“…[2,3] Particularly,t he advance in alkaline membrane technologies has stimulated intensive studies on HzOR to be used in practical HzFCs. [4] In this context, enormous efforts have been devoted towards developing efficient, low-cost anode electrocatalysts for HzOR to replace the costly state-of-the-art platinum (Pt) based nanomaterials, [5][6][7] along with optimizing the electrode fabrication craft. [8,9] Recently,s ingle-atom catalysts,e specially atomically dispersed metals anchored on conductive nitrogen (N)-doped carbons (AMCs), have been intensively studied for numerous applications [10][11][12][13][14][15] because of their maximized atom utilization, unusual electronic structure and intriguing properties that differ from their nanoparticles (NPs) counterpart in terms of that is,improved activity and/or selectivity.…”

“…c) CV curves of SeNCM-1000 in 1 m KOH with 100 mm N 2 H 4 at different scan rates(5,10,15,20,40,100 mVs À1 ). b) CV curves of SeNCM-x,S epowder and NCM-1000 for HzOR (100 mm N 2 H 4 ,1m KOH, scan rate 5mVs À1 ).…”