The use of a computation-guided method and the discovered structure–property relationship would establish a rational strategy to aid the development of ethanol oxidation reaction (EOR) catalysts for possible commercialization of direct ethanol fuel cells. Here, we investigate the promotion roles of additive metals in ternary Pt–Sn–Ag catalysts toward EOR via a combination of density functional theory calculation and experimental evidence. By calculating the EOR energetics, the promotion roles of Sn and Ag were revealed from the viewpoints of electronic and structural effects, respectively: (1) The addition  of Sn and Ag on Pt essentially reduce the reaction energy and activation barrier of the second two-electron transfer process of EOR, facilitating the oxidation of acetaldehyde to acetic acid; (2) a homogeneous Pt–Sn–Ag surface configuration strengthens the adsorption energy of ethanol, thus improving the activity for ethanol oxidizing to acetaldehyde. Experimentally, various Pt–Sn–Ag nanorod catalysts with different surface configurations were synthesized, and their electrochemical performances demonstrate the two EOR promotion effects as predicted. Notably, our extended Pt6–Sn–Ag nanorod catalyst shows remarkably enhanced EOR activity and stability, highlighting a homogeneous Pt–Sn–Ag surface configuration as an optimal structure for EOR catalysts.

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A facile strategy for preparing carbon-supported Co95Pt5 nanocatalysts (NCs) with low platinum (Pt) loading and high Pt utilization via thermal reduction treatment in a carbon monoxide (CO) atmosphere is reported. By cross-referencing results of microscopy, X-ray spectroscopy, and electrochemical analysis, we demonstrate that the Pt atoms tend to form disordered atomic clusters capping on the Co nanoparticle surface. The values of unfilled d-states (h Ts) extracted from X-ray absorption near-edge spectroscopy were used to calculate the d-band vacancies of Pt. Accordingly, CoPt-CO570 (reduced in CO at 570 K) possesses the lowest h Ts value (0.302) (i.e., the lowest Pt d-band vacancies) among experimental samples, indicating a strong electron relocation from Co atoms. Such electron relocations are attributed to the high extent of the heteroatomic intermix between Pt and Co atoms and thus improves the oxygen reduction reaction activity of CoPt-CO570. For providing further evidence, structural and electrochemical properties for H2 and NaBH4 reduction-prepared CoPt NCs are compared as the control. This work may represent an appealing step toward the structural design of low Pt and high activity catalysts for fuel cell cathode catalysts.

Hydrogen evolution reaction (HER) plays a key role in combating an ever-growing imbalance and adverse climatic issues. Thus far, Pt-based catalysts are treated as "the Holy Grail" for HER and none have surpassed them. However, as the reaction sites are present only on the catalyst surface, Pt utilization is severely hampered. Scaling down the catalyst nanoparticles is a vital approach to maximize the Pt utilization. To address this issue, we fabricated Pt x Pd y (x/y = 1/2, 1/1, and 2/1) bimetallic nanocatalysts (NCs) downsized up to ∼1.2 nm with ultralow metal loading (∼1−3 wt %) and remarkable catalytic performance via a deposition−precipitation method on a carbon support. In the optimum case, the NC with a x/y ratio of 1/1 (i.e., Pt 1 Pd 1 ) exhibits an outstanding mass activity (MA) of 9.57 A mg Pt −1 at 0.05 V versus normal hydrogen electrode in acidic medium (0.5 M H 2 SO 4 ) in HER. This result is 7.4-times enhanced compared to that of the Pt/C NC. Moreover, the Pt 1 Pd 1 NC retains 81% of its MA (7.74 A mg Pt −1 ) when operated in the chronoamperometric stability test (while 39% decay in MA is observed for the Pt/ C NC) up to 12 h. By screening the results of electron microscopy, X-ray spectroscopy, and electrochemical analysis, we revealed that such a substantial improvement is resulted from the decoration of the Pt trimer with high surface coverage and local structure ordering in the Pd crystal. Results of Pt x Pd y with different atomic Pt sizes are compared as a reference for rationalizing the development of ultralow-noble metal loading PtPd NCs in HER.

Pt−oxygen-containing species (Pt-OCS) catalysts, in which OCS (e.g., metal-oxides) are decorated on a Pt surface, possess enhanced ethanol oxidation reaction (EOR) activity and stability compared with pure Pt and are promising in practical applications of direct ethanol fuel cells. We investigate the promotion roles of Pt-OCS electrocatalysts toward the EOR via a combination of density functional theory (DFT) calculations and experiments, providing a rational design strategy for Pt-OCS catalysts. It is revealed that Pt-AuO and Pt-SnO excel in EOR activity and stability, respectively, among the DFT screening of various Pt-OCS systems, and this is confirmed by the following experiments. Moreover, an optimized Pt-AuSnO catalyst is proposed by DFT calculations, taking advantage of both Pt-AuO and Pt-SnO. The as-prepared Pt-AuSnO catalyst delivers an EOR activity that is 9.7 times higher than that of Pt and shows desired stability. These findings are expected to elucidate the mechanistic insights into Pt-OCS materials and lead to advanced EOR electrocatalysts.