Boosting Both Electrocatalytic Activity and Durability of Metal Aerogels via Intrinsic Hierarchical Porosity and Continuous Conductive Network Backbone Preservation

Abstract

As an emerging class of highly and hierarchically porous materials with continuous conductive metal network backbones, metal aerogels have unleashed tremendous potential in various fields, especially in electrocatalysis. However, it remains a great challenge to maximize the utilization of the intrinsic structural advantages of metal aerogels due to the collapse of their structure during conventional electrode preparation caused by their brittle character. Herein, a general in situ silicone‐confined gelation strategy is developed to integrate metal aerogels (PtPd, PtAg, PdAg, and AuAg) into/onto macroporous skeletons (carbon cloth, carbon fiber foam, and nickel foam). The composite materials have good mechanical flexibility, and can be utilized directly under the condition of well‐preserved intrinsic structure of metal aerogels. This not only results in more efficient electron transfer and faster mass transport, but also eliminates Ostwald ripening and aggregation, leading to both remarkably enhanced activity and durability when compared to that made by conventional ink drop coating with collapsed and compressed structure. This work represents a significant breakthrough for metal aerogels, and provides inspiration for electrocatalyst design with both high activity and durability.

Ultrasmall Gold Nanoclusters‐Enabled Fabrication of Ultrafine Gold Aerogels as Novel Self‐Supported Nanozymes

“…As an emerging new class of aerogel materials, metallic aerogels well retain merits of both metals and aerogels, exhibiting many attractive features, including abundant porous structures, ultralow density, metallic backbone, and self‐supportability. [ 1–3 ] Consequently, metal aerogels have been widely exploited for application in diverse fields such as catalysis, [ 4,5 ] sensing, [ 6,7 ] and actuation. [ 8 ] With the rapid advances in recent years, researchers have developed various strategies for fabricating metal aerogels, which can be classified into one‐step strategy and two‐step strategy depending on the type of employed “precursors”.…”

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Consequently, metal aerogels have been widely exploited for application in diverse fields such as catalysis, [4,5] sensing, [6,7] and actuation. [8] With the rapid advances in recent years, researchers have developed various strategies for fabricating metal aerogels, which can be classified into one-step strategy and two-step strategy depending on the type of employed "precursors".

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Tungsten Oxide/Reduced Graphene Oxide Aerogel with Low‐Content Platinum as High‐Performance Electrocatalyst for Hydrogen Evolution Reaction

“…Until now, many efforts have been made on the adequate exposure of all the Pt species in the entire electrode, the activity modulation of each active site, and the stabilization of the active sites during the electrocatalysis. [15] Due to the large surface area, an interconnected 3D network, hierarchical porosity, and the feasibility of structure and composition design of their backbones, aerogels have drawn growing attention, emerged as good candidates for electrocatalysts or their supports, [16][17][18][19][20][21][22][23][24] and shown remarkable electrocatalytic performance in HER. [25] However, the aerogel-based HER electrocatalysts are still limited and mainly restricted to PtAu and AuRh noble-metal backbone aerogels.…”

Sub‐Monolayer YOx/MoOx on Ultrathin Pt Nanowires Boosts Alcohol Oxidation Electrocatalysis

“…The introduction of oxophilic metals, including Mo, Ru, and Rh, has been proven a good way for alleviating the CO poisoning because they are easier to generate the adsorbed hydroxyl group (OH ads ) at lower potential. [14,25,[41][42][43][44][45][46] Despite much progress has been made in the functional mechanism of Pt-based alloy catalysts, exploring a new catalyst system for restricting the CO poisoning issue is still a grand challenge till date.…”

“…[14][15][16][17][18] To address these issues, an efficient strategy is to combine Pt and other metals (such as Ni, Cu, Fe, and Ga) to form stable bimetallic or trimetallic alloys. [19][20][21][22][23][24][25][26] By further precisely designing the nanostructures of Pt-based catalysts with tailored sizes, dimensions, morphologies, or compositions, the welldesigned Pt-based alloys can not only reduce the consumption of Pt, but also achieve considerably enhanced activities. Especially, the ultrathin structure (generally <2 nm) can expose more surface active sites to achieve the high utilization of Pt atoms, which is thus considered to be an ideal platform for boosting electrocatalytic activity.…”