Preparation of Pt-skin PtRhNi Nanoframes Decorated with Small SnO₂ Nanoparticles as an Efficient Catalyst for Ethanol Oxidation Reaction

Abstract

Pt-based nanoframes are one of the most promising catalysts for ethanol oxidation reaction in direct ethanol fuel cells. It is important to understand the mechanisms responsible for creating these hollow nanoframe-based catalysts. Herein, for the first time, Pt-skin PtRhNi rhombic dodecahedral nanoframes were decorated with small SnO 2 nanoparticles and were used as an efficient catalyst for the ethanol oxidation reaction. Moreover, by combining the ex situ scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy observations at various stages of synthesis, along with density functional theory calculations, it was possible to track the synthesis route of solid rhombic dodecahedral PtRhNi nanoparticles, which are the precursors of PtRhNi nanoframes. After the chemical etching of the Ni core from solid PtRhNi nanoparticles, the obtained nanoframes were decorated with SnO 2 nanoparticles. The resulting SnO 2 @PtRhNi heteroaggregates were deposited on highsurface-area carbon and electrochemically tested, showing a 6-fold higher mass activity and 10-fold higher specific activity toward ethanol oxidation reaction than commercially available Pt catalysts.

Advanced Catalytic Materials for Ethanol Oxidation in Direct Ethanol Fuel Cells

“…In addition to the widely-developed nanowires, many novel nanostructures, such as nanocages and nanoframes, have been constructed to accommodate more abundant active sites and large surface-area-to-volume ratios. Also, a few ternary metal-based catalysts (such as PtCuNi [68], PtRhNi [61], PtMoNi [69], and PtAuSn [70]) with precise composition control have shown increased EOR selectivity. The PtRhNi polyhedra nanoparticles [71] were chemically etched to form Pt-skin PtRhNi nanoframes which were then attached with SnO 2 nanoparticles [61] (Figure 4f-i).…”

“…Also, a few ternary metal-based catalysts (such as PtCuNi [68], PtRhNi [61], PtMoNi [69], and PtAuSn [70]) with precise composition control have shown increased EOR selectivity. The PtRhNi polyhedra nanoparticles [71] were chemically etched to form Pt-skin PtRhNi nanoframes which were then attached with SnO 2 nanoparticles [61] (Figure 4f-i). The hybrid SnO 2 @PtRhNi/C catalysts exhibited excellent mass activity and specific activity that were 6-fold and 10-fold higher than the commercial Pt/C catalyst, respectively (Figure 4j).…”

Synthesis and Application of Platinum-based Hollow Nanoframes for Direct Alcohol Fuel Cells

“…Compared with PtCu nanocrystals and PtCuRh nanoparticles, vertex-reinforced PtCuRh NFs achieve an enhanced current density due to more active sites and coordination options. Also, the introduction of Rh promotes the oxidation of ethanol, which provides a direction for breaking C-C bonds and the full oxidation of ethanol 54,106 . More importantly, the anti-poisoning ability is an essential parameter to assess the sustainable performance of catalysts in alcohol oxidation, especially the strong adsorption of CO on the catalytic surface during the reaction, where the oxidation peak potential and onset potential of PtCuRh materials are more negative compared to commercial Pt/C and PtCu material (Fig.…”

PtPdMo Nanosheets with Controllable Synthesis for Enhanced Oxygen Reduction Reactions

“…Besides, lots of researches have proved that the morphologies of Pt-based catalysts greatly influence their ORR properties . From this perspective, Pt-based catalysts with a variety of morphologies have been designed, such as nanoframes, nanowires, nanoflowers, nanosheets, and so on. Among them, ultrathin nanosheets have received extensive attention on account of their unique morphologies and electronic structures. , For instance, Luo et al synthesized suprathin PdMo nanosheets through a simple chemical method with the assistance of Mo­(CO) 6 .…”