Polyelectrolyte-Induced Stereoassembly of Grain Boundary-Enriched Platinum Nanoworms on Ti₃C₂T_x MXene Nanosheets for Efficient Methanol Oxidation

Abstract

Direct methanol fuel cells with high energy conversion efficiency and low hazard emissions have aroused great attention from both academic and industrial communities, but their large-scale commercial application has been blocked by high costs as well as short lifespan of the anode Pt catalysts. Here, we demonstrate a simple and scalable noncovalent strategy for the synthesis of quasi-one-dimensional (1D) Pt nanoworms grown on poly­(diallyldimethyl-ammonium chloride) (PDDA)-functionalized Ti3C2T x nanosheets as anode catalysts for methanol electrooxidation. Interestingly, the introduction of PDDA on Ti3C2T x nanosheets can not only effectively adjust their surface charge property to strengthen the electrostatic interaction between metal and support but also induce the stereoassembly of worm-shaped Pt nanocrystals with abundant catalytically active grain boundaries, which enable the resulting hybrid to express high electrocatalytic activity, remarkable durability, and strong antipoisoning ability for methanol electrooxidation, which are better than those of the traditional Pt nanoparticle electrocatalysts loaded on carbon black, carbon nanotubes, reduced graphene oxide, and MXene matrixes. Theoretical simulations disclose that the more stable worm-shaped Pt configuration with an optimized electronic structure on the Ti3C2T x surface possesses a weaker CO adsorption ability than that of the Pt nanoclusters, thereby providing a dramatically enhanced and sustainable electrocatalytic performance.

Ultrafine Rh-Decorated 3D Porous Boron and Nitrogen Dual-Doped Graphene Architecture as an Efficient Electrocatalyst for Methanol Oxidation Reaction

“…To date, platinum (Pt) and Pt-based catalysts are the most frequently used anode catalysts in DMFCs because of their unique catalytic ability for methanol oxidation. − However, some challenging issues, such as the limited reserve, high price, and poor poisoning tolerance of Pt catalysts, have greatly hindered their further commercial-scale application in DMFCs. − Therefore, it is certainly worth searching non-Pt catalysts with acceptable costs but comparable catalytic performance. − Recently, rhodium (Rh) nanocrystal catalysts have received considerable attention because of their high catalytic activity for the electro-oxidation of organic small molecules. , More importantly, when compared with the conventional Pt catalysts, Rh-based catalysts are able to provide a greater resistance to the poisoning species (mainly CO), which is very favorable to extend the usable life of the DMFC devices . Nonetheless, nanostructured Rh catalysts easily suffer from agglomeration as well as insufficient electron conductivity during the electrocatalytic process, rendering a large loss of their catalytic activity.…”

Enabling methanol oxidation by an interacting hybrid nanosystem of spinel Co3O4 nanoparticle decorated MXenes

“…These peaks when deconvoluted reveal 6 peaks (Fig. 4d) which correspond to different interactions viz., Ti (2p 3/2 )-C (457.2 eV), Ti (2p 3/2 )-Ti (2p 3/2 ) (458 eV), Ti (2p 3/2 )-O (458.8 eV), Ti (2p 1/2 )-Ti (2p 1/2 ) (460.1 eV), C-Ti (2p 1/2 )-T x (463.6 eV), and Ti (2p 1/2 )-O (464.9 eV), 50,51 with T x being the hydrophilic terminations. Moreover, the C 1s spectrum (Fig.…”

“…4e) of TC is resolved into four peaks at 284.3, 284.9, 285.5, and 289 eV reflecting the C-C, C-N, CH x /C-O, and CvO interactions, respectively. 51 From the C-N interaction, the presence of N containing co-products of Ti 3 C 2 etching can be established. The surface area and porosity are studied by the Brunauer-Emmett-Teller (BET) method.…”

MoS2 quantum dot-decorated MXene nanosheets as efficient hydrogen evolution electrocatalysts

“…Firstly, 2D Ti 3 C 2 T x nanosheets were prepared by etching commercial Ti 3 AlC 2 powder in a LiF/HCl solution according to our previous studies. 30,31 The typical synthetic procedures for the MQDs/Ti 3 C 2 T x catalysts, for example, when the mass fraction of MoS 2 QDs was 5.0 wt%, are as follows: 40 mg of the as-obtained Ti 3 C 2 T x nanosheets were fully dispersed in 40 mL of ethyl alcohol and 40 mL of deionized water by sonication for 30 minutes. Next, 2.1 mL of MoS 2 QD solution (1 mg mL −1 ) was dropwise added to the above Ti 3 C 2 T x suspension with magnetic stirring for 30 minutes.…”

“…S1–S3†). 30,31 The obtained Ti 3 C 2 T x nanosheets with an average thickness of about 3 nm were then ultrasonically dispersed into an ethylene glycol solution to form a freestanding black suspension (Fig. S4 and S5†), where the introduction of ethylene glycol can effectively prevent the Ti 3 C 2 T x nanosheets from excess oxidation.…”