High stability and reactivity of defective graphene-supported Fe n Pt13−n (n = 1, 2, and 3) nanoparticles for oxygen reduction reaction: a theoretical study

Abstract

Recent experimental studies have shown that the FePt nanoparticles (NPs) assembled on graphene exhibit enhanced durability and catalytic activity for oxygen reduction reaction (ORR) than Pt-only catalysts. In this work, we have performed density functional theory calculations to investigate the stability and reactivity of several Fe n Pt 13-n NPs deposited on defective graphene for ORR, where n is adopted as 0, 1, 2, and 3, respectively. The results indicate that the alloying between Fe and Pt can enhance the stability of NPs and promote their oxygen reduction activity. Moreover, the monovacancy site in the graphene can provide anchoring sites for these bimetallic NPs by forming strong metal-substrate interaction, ensuring their high stability. Importantly, the O 2 adsorption on these composites is weakened in various ways, which is ascribed to the change in their averaged d-band center. Thus, these composites exhibit superior catalytic performance in ORR by providing a balance in the O 2 binding strength that allows for enhanced turnover. Our results may be useful to unravel the high stability and reactivity of defective graphene-FePt NPs for ORR from a theoretical perspective.

L12 Atomic Ordered Substrate Enhanced Pt-Skin Cu3Pt Catalyst for Efficient Oxygen Reduction Reaction

“…In contrast, commercial Pt/C suffered from severe aggregation (Figure S11). Therefore, it was speculated that the performance degradation of Pt-based bimetallic compounds was mainly caused by the oxidation and leaching of Cu atoms under the rigorous durability testing conditions, which was reported to be associated with the formation energy of the compound. , The formation energy calculated by DFT of d-Cu 3 Pt and o-Cu 3 Pt was −0.114 and −0.157 eV/atom, respectively, indicating the stronger bonding nature of Pt–Cu and stabilization of Cu within the L1 2 structure. The prohibited leaching of Cu in the ordered substrate was also verified via ICP–AES results because the Pt-to-Cu atom ratios of Pt-o-Cu 3 Pt/C and Pt-o-Cu 3 Pt/C were 0.85:1 and 0.44:1, respectively, after 5000 potential cycles.…”

“…Therefore, it was speculated that the performance degradation of Pt-based bimetallic compounds was mainly caused by the oxidation and leaching of Cu atoms under the rigorous durability testing conditions, which was reported to be associated with the formation energy of the compound. 67,68…”

Enhanced CO tolerance of Pt clusters supported on graphene with lattice vacancies

“…In addition, more recent HAADF-STEM measurements have even observed single Pt atoms dispersed on undoped [15,16] and nitrogendoped [17] graphene, which show high catalytic activities and CO tolerance. Theoretically, on the other hand, firstprinciples calculations based on density functional theory (DFT) have been performed extensively to clarify the properties of graphene-supported Pt clusters from viewpoints of geometric [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] and magnetic [35][36][37][38][39][40][41][42][43][44] structures, molecular adsorptions [45][46][47][48][49][50], CO tolerance [51][52][53][54], and catalytic reactions such as CO oxidation [55][56][57][58][59][60], decomposition of O 3…”