Integrating Pt₁₆Te Nanotroughs and Nanopillars into a 3D “Self‐Supported” Hierarchical Nanostructure for Boosting Methanol Electrooxidation

Abstract

To address the poor durability of Pt catalyst caused by CO poisoning, scientists mainly focus on designing Pt-based hybrids, that is, integration of other metal(s) with Pt. [4] Thanks to the synergistic effects between different metals (e.g., electronic and strain effect, [1a,5] bifunctional mechanism [1a,2a,6] ), Pt-based hybrids have been demonstrated to be effective in the improvement of the catalytic durability as well as the catalytic activity, and dependent on the integration of other metals, the cost is accordingly reduced to a certain extent. [4c,6b] The catalyst performance (i.e., catalytic activity and durability) of Pt-based hybrids is closely linked with components (e.g., Pd, [7] Au, [4b] Ag, [8] Ni, [2b,9] Te, [6a,10] Co, [4c,11] and Fe [5a] ), morphologies (e.g., sphere, [12] polyhedron, [9a] tube, [13] wire, [3a,7b] sheet, [10b] cage, [14] and frame [11] ), exposed facets, [9b,15] and the integration patterns of Pt with other metallic elements (e.g., core/shell [7b,12b] and alloyed [2,4c,13] ). To date, various Pt-based catalysts of high performance have been exploited. [16] Despite that, the preparations of most Pt-based catalyst inks mainly follow the conventional procedure: catalysts are physically mixed with carbon [17] and coated an electrode surface in the form of powder, [7b,17c,18] and thus, the decay of catalytic durability caused by carbon corrosion and random arrangement of particles is still unresolved issues.A few reports [19] have discovered that carbon-free closepacked catalyst particle arrays are capable of exhibiting better catalytic performances than the mixture of the corresponding catalyst and carbon powder, for example, Pt nanowire arrays synthesized with a template-less wet chemical method [19a] and close-packed PtTe nanotube array fabricated by a Langmuir-Blodgett (LB) technique. [19d] Despite these successes, to date, most of present close-packed nanoparticle arrays do not own "self-supported" features and thus lack enough mechanical strength, and the mobility of electrons between adjacent nanoparticles is severely restricted simply because of their physical contact.Herein, we transform Te nanowire (TeNW) array at an air/ water interface into a 3D "self-supported" Pt 16 Te hierarchical nanostructure by combining interfacial self-assembly and interface-oriented galvanic replacement (Scheme 1a-d). The Pt 16 Te To develop durable and low-price catalysts of methanol oxidation to commercialize direct methanol fuel cell, many attempts have been made at fabricating Pt-based hybrids by designing component-, morphology-, facet-, integrationpattern-varied nanostructures, and have achieved considerable successes. However, most of present catalysts still lack robust catalytic durability especially owing to the corrosion of mixed carbon and the poor mechanical stability of catalyst layer. Herein, Te nanowire array is transformed at an air/ water interface into a 3D Pt 16 Te hierarchical nanostructure via an interfaceconfined galvanic replacement reaction. As-formed...

Nanostructures and catalytic atoms engineering of tellurium‐based materials and their roles in electrochemical energy conversion

“…Specifically, a combination of interfacial self‐assembly and interface‐oriented current displacement can transform Te NWs arrays at the air/water interface into 3D “self‐supporting” Pt 16 Te hierarchical nanostructures (Figure 9Ai). 46 Such special nanostructures consist of asymmetric nanogrooves and nanopillars, wherein the nanopillars are perpendicular to the nanogrooves and loosely arranged. Pt 16 Te nanostructures exhibited remarkable catalytic activity and long‐term durability used as catalysts for methanol electrooxidation (Figure 9Aii,iii).…”

“…(iii) Cycling stability of Pt 16 Te and Pt/C. Reproduced with permission: Copyright 2021, Wiley‐VCH 46 . (B) (i) Schematic diagram of surface restructuring of PtTeCo nanorods.…”

“…To achieve the design of high‐performance electrocatalysts, many strategies for nanostructures and catalytic atoms engineering have been developed, such as chemical/physical/multiplex templating strategies, heteroatom doping, vacancy/defect engineering, and phase engineering 42,43 . By tuning the intrinsic physicochemical properties and catalytic centers, 44 the engineered Te NMs may provide new electrocatalysts to meet the specific requirements of novel catalytic applications 45–47 . Although some reviews have briefly described the synthesis and properties of Te NMs; few has focused on the topics of engineering Te NMs for electrochemical energy conversion 48 .…”

Morphological tuning engineering of Pt@TiO2/graphene catalysts with optimal active surfaces of support for boosting catalytic performance for methanol oxidation

“…1–3 At present, platinum-based electrocatalysts benefiting from high performance have aroused intensive research on the methanol oxidation reaction (MOR) in DMFCs. 4–6 Nevertheless, their expensive price, sluggish anodic oxidation kinetics, vulnerability to CO intermediate poisoning, and inefficient utilization of Pt metal catalysts severely limit their large-scale development. 7–9 Thus, significant efforts have been devoted to investigating solutions for boosting electrocatalyst activity and stability for the further commercialization of fuel cells.…”

Electron density regulation of Pt–Co nanoalloys via P incorporation towards methanol electrooxidation

“…The past several years have witnessed the introduction of non-metal elements, e.g. N, [10][11][12] P, 13,14 and Te, 15 into the platinum (Pt)-based nanoalloys to address their high cost and low electrochemical stability for the methanol oxidation reaction (MOR). Theoretically, alloying a non-metal element with higher electronegativity into Pt is favorable for overcoming its susceptibility to the poisonous carbon monoxide (CO)-like intermediates generated during the MOR.…”