Developing efficient and low‐cost replacements for precious metals as electrocatalysts active in electrochemical reactions—the oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR)—is a top priority in renewable energy technology. In this work a highly active and very stable trifunctional electrocatalyst composed of Co2P embedded in Co, N, and P multi‐doped carbon has been synthesized using zeolitic imidazolate frameworks as precursors. The synergistic effects between Co2P and the multi‐heteroatom‐doped carbon substrates afford materials having electrocatalytic activities for HER, OER, and ORR, which are comparable—or even superior to—those of commercial RuO2 or Pt/C catalysts. Density functional theory calculations show that Co2P has a higher density of states at the Fermi level than ConP (0 < n < 2), which promotes electron transfer and intermediates adsorption in the catalytic process. Zinc–air batteries and water splitting devices assembled using the materials as electrode electrocatalysts show good performance and outstanding stability. This work represents a breakthrough in improving the catalytic performance of non‐precious metal electrocatalysts for OER, HER, and ORR, and opens new avenues for clean energy generation.
Two‐dimensional conjugated aromatic networks (CAN) with ultra‐thin conjugated layers (ca. 3.5 nm) and high single‐metal‐atom‐site density (mass content of 10.7 wt %, and 0.73 metal atoms per nm2) are prepared via a facile pyrolysis‐free route involving a one‐step ball milling of the solid‐phase‐synthesized polyphthalocyanine. These materials display outstanding oxygen reduction reaction (ORR) mass activity of 47 mA mgcat.−1 represents 1.3‐ and 6.4‐fold enhancements compared to Pt and Pt/C in benchmark Pt/C, respectively. Moreover, the primary Zn‐air batteries constructed with CAN as an air electrode demonstrate a mass/volume power density of 880 W gcat.−1/615 W cmcat.−3 and stable long‐term operation for 100 h. This strategy offers a new way to design high‐performance electrocatalysts with atomic precision for use in other energy‐storage and conversion applications.
Bimetal nitrogen-doped carbon with both Fe and Co, derived from the pyrolysis carbon of iron and cobalt phthalocyanine-based conjugated polymer networks, possesses a few-layer graphene-like texture with hierarchical porosity in meso/micro multimodal pore size distribution. The novel electrocatalyst exhibits Pt-like catalytic activity and much higher catalytic durability for oxygen reduction.
Exploring sustainable and high-performance electrocatalysts for the oxygen reduction reaction (ORR) is the crucial issue for the large-scale application of fuel cell technology. A new strategy is demonstrated to utilize the biomass resource for the synthesis of N-doped hierarchically porous carbon supported single-atomic Fe (SA-Fe/NHPC) electrocatalyst toward the ORR. Based on the confinement effect of porous carbon and high-coordination natural iron source, SA-Fe/NHPC, derived from the hemin-adsorbed bio-porphyra-carbon by rapid heat-treatment up to 800 °C, presents the atomic dispersion of Fe atoms in the N-doped porous carbon. Compared with the molecular hemin and nanoparticle Fe samples, the as-prepared SA-Fe/NHPC exhibits a superior catalytic activity (E = 0.87 V and J = 4.1 mA cm , at 0.88 V), remarkable catalytic stability (≈1 mV negative shift of E , after 3000 potential cycles), and outstanding methanol-tolerance, even much better than the state-of-the-art Pt/C catalyst. The sustainable and effective strategy for utilizing biomass to achieve high-performance single-atom catalysts can also provide an opportunity for other catalytic applications in the atomic scale.
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