Facile Synthesis of Pd and PdPtNi Trimetallic Nanosheets as Enhanced Oxygen Reduction Electrocatalysts

Abstract

Pd nanosheets, [11] the derivative PdCu nanosheets, [12] PtPb/Pt nanoplates, [13] and PtPdM (M = Ni, Co, and Fe) nanosheets. [1] Another strategy to improve the activity and stability of catalysts in electrocatalytic reactions is to form alloys; [14][15][16][17] and alloying with non-noble metals may help reduce the cost of the catalyst further. [18][19][20][21] Compared to the well-studied bimetallic alloys, trimetallic alloys can possess a more complex alloy lattice that has better reactivity and stability, and the extra composition could further fine-tune the properties of the catalyst. [18,[22][23][24] For instance, Xiong et al. reported a PtFeCo trimetallic tristar nanostructure with enhanced hydrogen evolution reaction activity. [23] The addition of Fe and Co lowered the d-band center of Pt, enhanced the reaction activity and reduced the cost of the catalyst. Other reported trimetallic catalysts include the PtCuCo hollow nanospheres, [25] PtPdNi nanocages, [26] and PtNiAu alloy nanostructures. [27] Previously, our group reported a solvothermal synthesis of Pd-Pt alloy nanosheets. [8] Herein, we further developed a wet chemical method to synthesize wrinkled ultrathin Pd and PdPtNi trimetallic nanosheets. Because of facile reaction conditions, the reaction process and formation mechanism of the ultrathin Pd nanosheets were comprehensively studied. It was found that the degree of wrinkling increased with the increase in temperature and the progress of reaction, and the CO formed in situ by the decomposition of the solvent N,Ndimethylformamide (DMF) is responsible for 2D growth. Trimetallic PdPtNi nanosheets were obtained by depositing Pt and Ni onto the Pd nanosheets, with the atomic composition of the PdPtNi nanosheets readily adjusted by the molar ratio of the precursors. The ORR catalytic performance of the nanosheets was demonstrated. Among all the nanosheets, the Pd 9 Pt 1 Ni 1 nanosheets showed the highest half-potential of 0.928 V (vs reversible hydrogen electrode (RHE)). The nanosheets also exhibited improved stability, with the half-potential shifted negatively only by 10.6 mV after 10 000 cycles. Results and DiscussionPd nanosheets were synthesized by using a facile wet chemical method. Typically, 4.5 mg Na 2 PdCl 4 was first dissolved in 6 mL of DMF and 4 mL of ethylene glycol (EG), followed byThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smll.202103665.

A PdMn bimetallene for low-energy electrocatalytic hydrogen generation coupled with formate oxidation

“…When MnCl 2 is used to replace manganese acetoacetone, PdMn nanoparticles are formed because the anions have a great influence on the reduction kinetics and nucleation process of the metal. 35 These results indicate the importance of appropriate precursors for the synthesis of the well-defined PdMn bimetallene.…”

PdCu Bimetallene for Enhanced Oxygen Reduction Electrocatalysis

“…DMF holds a prominent role in the synthesis of 2D nanomaterials. At high temperatures, CO can be produced from the decomposition of DMF in the presence of KOH, which can adsorb on the (111) plane of the nucleus, effectively inducing the selective growth of the 2D nanostructure. , Then, we excavated the contribution of KOH content to the geometrical topology. We prepared different PdCu bimetallene samples by the addition of various KOH amounts (Figure S5).…”

Bimetallic Face-Centered Cubic Pd–Ag Nano-dendritic Alloys Catalysts Boost Ethanol Electrooxidation

“…To improve the catalytic performance of electrocatalysts, there is a great interest in the research of non-platinum electrocatalysts. − Palladium is one of the platinum group metals; as an anodic catalyst, it shows great potential in electrocatalysis because it possesses excellent catalytic activity and stability in aqueous electrolytes. − Also, the electron structure of Pd can be optimized by alloying with other elements like nickel, , copper, , bismuth, , and tin ,, to form Pd-based alloys. These improve the electrocatalytic activity toward EOR effectively. − In addition, some loadings can greatly improve the utilization of noble metal atoms . Recently, revealing the synergistic effects (strain effect and ligand effect) of Pt/Pd-based catalysts to promote the development of electrocatalysts has become a worldwide hotspot.…”