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Recently, considerable attention has been paid to the stabilization of atomic platinum (Pt) catalysts on desirable supports in order to reduce Pt consumption, improve the catalyst stability, and thereafter enhance the catalyst performance in renewable energy devices such as fuel cells and zinc-air batteries (ZABs). Herein, we rationally designed a novel strategy to stabilize atomic Pt catalysts in alloyed platinum cobalt (PtCo) nanosheets with trapped interstitial fluorine (SA-PtCoF) for ZABs. The trapped interstitial F atoms in the PtCoF matrix induce lattice distortion resulting in weakening of the Pt–Co bond, which is the driving force to form atomic Pt. As a result, the onset potentials of SA-PtCoF are 0.95 V and 1.50 V for the oxygen reduction and evolution reactions (ORR and OER), respectively, superior to commercial Pt/C@RuO 2 . When used in ZABs, the designed SA-PtCoF can afford a peak power density of 125 mW cm −2 with a specific capacity of 808 mA h g Zn −1 and excellent cyclability over 240 h, surpassing the state-of-the-art catalysts. 

Abstract Atomically dispersed FeN₄active sites have exhibited exceptional catalytic activity and selectivity for the electrochemical CO₂reduction reaction (CO2RR) to CO. However, the understanding behind the intrinsic and morphological factors contributing to the catalytic properties of FeN₄sites is still lacking. By using a Fe‐N‐C model catalyst derived from the ZIF‐8, we deconvoluted three key morphological and structural elements of FeN₄sites, including particle sizes of catalysts, Fe content, and Fe−N bond structures. Their respective impacts on the CO2RR were comprehensively elucidated. Engineering the particle size and Fe doping is critical to control extrinsic morphological factors of FeN₄sites for optimal porosity, electrochemically active surface areas, and the graphitization of the carbon support. In contrast, the intrinsic activity of FeN₄sites was only tunable by varying thermal activation temperatures during the formation of FeN₄sites, which impacted the length of the Fe−N bonds and the local strains. The structural evolution of Fe−N bonds was examined at the atomic level. First‐principles calculations further elucidated the origin of intrinsic activity improvement associated with the optimal local strain of the Fe−N bond. 

Abstract Ammonia (NH₃) electrosynthesis gains significant attention as NH₃is essentially important for fertilizer production and fuel utilization. However, electrochemical nitrogen reduction reaction (NRR) remains a great challenge because of low activity and poor selectivity. Herein, a new class of atomically dispersed Ni site electrocatalyst is reported, which exhibits the optimal NH₃yield of 115 µg cm⁻²h⁻¹at –0.8 V versus reversible hydrogen electrode (RHE) under neutral conditions. High faradic efficiency of 21 ± 1.9% is achieved at ‐0.2 V versus RHE under alkaline conditions, although the ammonia yield is lower. The Ni sites are stabilized with nitrogen, which is verified by advanced X‐ray absorption spectroscopy and electron microscopy. Density functional theory calculations provide insightful understanding on the possible structure of active sites, relevant reaction pathways, and confirm that the Ni‐N₃sites are responsible for the experimentally observed activity and selectivity. Extensive controls strongly suggest that the atomically dispersed NiN₃site‐rich catalyst provides more intrinsically active sites than those in N‐doped carbon, instead of possible environmental contamination. This work further indicates that single‐metal site catalysts with optimal nitrogen coordination is very promising for NRR and indeed improves the scaling relationship of transition metals. 

Abstract FeN₄moieties embedded in partially graphitized carbon are the most efficient platinum group metal free active sites for the oxygen reduction reaction in acidic proton‐exchange membrane fuel cells. However, their formation mechanisms have remained elusive for decades because the Fe−N bond formation process always convolutes with uncontrolled carbonization and nitrogen doping during high‐temperature treatment. Here, we elucidate the FeN₄site formation mechanisms through hosting Fe ions into a nitrogen‐doped carbon followed by a controlled thermal activation. Among the studied hosts, the ZIF‐8‐derived nitrogen‐doped carbon is an ideal model with well‐defined nitrogen doping and porosity. This approach is able to deconvolute Fe−N bond formation from complex carbonization and nitrogen doping, which correlates Fe−N bond properties with the activity and stability of FeN₄sites as a function of the thermal activation temperature.