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Electrocatalytic conversion of organic small molecules is a promising technique for value-added chemical productions but suffers from high precious metal consumption, poor stability of electrocatalysts and tedious product separation. Here, a Pd/NiMoO4/NF electrocatalyst with much lowered Pd loading amount (3.5 wt.%) has been developed for efficient, economic, and ultra-stable glycolate synthesis, which shows high Faradaic efficiency (98.9%), yield (98.8%), and ultrahigh stability (1500 h) towards electrocatalytic ethylene glycol oxidation. Moreover, the obtained glycolic acid has been converted to value-added sodium glycolate by in-situ acid-base reaction in the NaOH electrolyte, which is atomic efficient and needs no additional acid addition for product separation. Moreover, the weak adsorption of sodium glycolate on the catalyst surface plays a significant role in avoiding excessive oxidation and achieving high selectivity. This work may provide instructions for the electrocatalyst design as well as product separation for the electrocatalytic conversions of alcohols. Here, the authors report a path for electrocatalytic conversions of alcohols through in-situ acid-base reaction and the design of electrocatalysts. In this work, the electrocatalyst had reduced Pd content, improved efficiency, and lowered costs. [ABSTRACT FROM AUTHOR]

Electrocatalytic hydrogen production under acidic conditions is of great importance for industrialization in comparison to that in alkaline media, which, unfortunately, still remains challenging due to the lack of earth‐abundant, cost‐effective and highly active anodic electrocatalysts that can be used durably under strongly acidic conditions. Here we report an unexpected finding that manganese oxide, a kind of common non‐noble catalysts easily soluble in acidic solutions, can be applied as a highly efficient and extremely durable anodic electrocatalyst for hydrogen production from an acidic aqueous solution of alcohols. Particularly in a glycerol solution, a potential of as low as 1.36 V (vs. RHE) is needed at 10 mA cm−2, which is 270 mV lower than that of oxygen evolution reaction (OER), to oxidize glycerol into value‐added chemicals such as formic acid, without oxygen production. To our surprise, the manganese oxide exhibits extremely high stability for electrocatalytic hydrogen production in coupling with glycerol oxidation for longer than 865 hours compared to shorter than 10 h for OER. Moreover, the effect of the addition of glycerol on the electrochemical durability has been probed via in situ Raman spectroscopic analysis and density functional theory (DFT) calculations. This work demonstrates that acid‐unstable metal oxide electrocatalysts can be used robustly in acidic media under the presence of certain substances for electrochemical purposes, such as hydrogen production. [ABSTRACT FROM AUTHOR]

Hierarchically porous zeolites have been widely explored for catalytic applications owing to their high specific surface area, large pore volume, favorable mass transfer capability and abundant acidic sites. Herein we report the facile synthesis of Ni‐doped hierarchically Beta zeolite (Ni−H‐beta) via one‐pot hydrothermal method, in which Ni is uniformly doped into the zeolite crystalline skeleton in the form of Ni3+ without any nickel oxides being found. The prepared Ni−H‐beta zeolite shows high performance towards the electrocatalytic methanol oxidation reaction (MOR) with a high current density of 1450 A g−1 at 1.65 V vs RHE, which is higher than most non‐precious MOR electrocatalysts. More importantly, the electrochemical MOR performance has been identified to be closely related to the acidic property of the prepared samples. The increase in Al concentration resulted in the formation of strong acid sites, and the consequent MOR activity enhancement. These results provide valuable knowledge and favor the application of transition metals doped hierarchical zeolite for electrocatalytic MOR. [ABSTRACT FROM AUTHOR]

Although Pt/C catalysts show relatively high activities for the oxygen reduction reaction (ORR) and great potential for use in polymer electrolyte membrane fuel cells, the large amount of Pt required and the poor stability of Pt/C-based catalysts remain big challenges. Herein, mesoporous Na4Ge9O20 micro-crystals have been successfully synthesized to serve as a new kind of electrocatalyst support owing to its special structural characteristics and high structural stability. After loading a low amount of Pt (5 wt %) nanoparticles of 2-5 nm in diameter, the obtained mesoporous Pt/Na4Ge9O20 composite shows not only high electrocatalytic activity for ORR in both acidic and alkaline electrolyte media, which are comparable to those of conventional 20 wt % Pt/C, but also remarkably enhanced Pt mass-specified ORR current density and durability. Synergetic catalytic effects between loaded Pt and the support for the ORR activity has been proposed. [ABSTRACT FROM AUTHOR]

Hydrogen production by electrocatalytic water splitting is an efficient and economical technology, however, is severely impeded by the kinetic-sluggish and low value-added anodic oxygen evolution reaction. Here we report the nickel-molybdenum-nitride nanoplates loaded on carbon fiber cloth (Ni-Mo-N/CFC), for the concurrent electrolytic productions of high-purity hydrogen at the cathode and value-added formate at the anode in low-cost alkaline glycerol solutions. Especially, when equipped with Ni-Mo-N/CFC at both anode and cathode, the established electrolyzer requires as low as 1.36 V of cell voltage to achieve 10 mA cm−2, which is 260 mV lower than that in alkaline aqueous solution. Moreover, high Faraday efficiencies of 99.7% for H2 evolution and 95.0% for formate production have been obtained. Based on the excellent electrochemical performances of Ni-Mo-N/CFC, electrolytic H2 and formate productions from the alkaline glycerol solutions are an energy-efficient and promising technology for the renewable and clean energy supply in the future. Hydrogen production by electrocatalytic water splitting is limited by the sluggish evolution kinetics of low value-oxygen. Here, authors show concurrent electrolytic productions of H2 and glycerol oxidation to formate by utilizing Ni-Mo-N/CFC electro-catalyst as both anodic and cathodic catalysts. [ABSTRACT FROM AUTHOR]

Highly active and low‐cost non‐noble metal electrocatalysts for hydrogen oxidation reaction (HOR) are crucial for the large‐scale applications of fuel cells, which, unfortunately, are rarely documented up to now. Here, a facile one‐step strategy to fabricate W2C nanoparticles (≈3 nm) encased in N, P‐doped few layer carbon materials (W2C@N,P‐C, WNPC) as an efficient non‐noble metal HOR electrocatalyst simply by calcining the mixture of recrystallized phosphotungstic acid and dicyandiamide is reported. The obtained WNPC catalyst shows extraordinarily high HOR activities (1.03/0.91/0.84 mA cm−2 at 0.05 V vs reversible hydrogen electrode in 0.1 m HClO4/0.1 m KOH/0.1 m neutral phosphate buffered saline electrolytes, respectively), excellent durability during accelerated degradation tests for 10 000 cycles, and outstanding CO tolerance. These high performances are attributed to the uniform structure of WNPC, and more essentially, the synergistic effect among N, P, and C species which elevates the reducibility of WNPC, favoring the generation of abundant HOR active sites. [ABSTRACT FROM AUTHOR]

Exploring highly active, cost-effective and durable oxygen reduction reaction (ORR) electrocatalysts as substitutes for the rare platinum-based catalysts is of great significance in energy conversion and storage devices, such as alkaline fuel cells, metal-air batteries, etc. Herein, we fabricated a new type ORR electrocatalyst of Ni Co nanocrystal alloy encapsulated in N-doped carbon nanotubes (NCNTs) through a facile, scalable route utilizing nickel acetate and cobalt chloride as metallic Ni and Co precursors, thiourea as a nitrogen and carbon source, respectively, under a Ni/Co atomic ratio of 3:7 at 700 °C. The obtained nanocomposite catalyst NiCo@NCNT-700 exhibited an outstanding ORR activity close to that of the state-of-the-art Pt/C catalyst and superior operational durability under alkaline conditions, which could be attributed to the co-contributions among the uniformly distributed Ni Co alloy nanoparticles, graphitic NCNTs and the formation of Co N species. This work provides a new insight for the rational design and development of efficient non-noble metal electrocatalysts by integrating electrochemically active units into the nanocomposite for challenging electrochemical energy-related technologies. [ABSTRACT FROM AUTHOR]

A novel kind of N-doped hierarchically porous carbon materials (HPC-Ns) has been successfully synthesized with hierarchically macro/mesoporous silica as a hard template followed by a simple N-doping procedure using low-cost and nontoxic urea as the nitrogen source. The synthesized HPC-N samples demonstrated extensive three-dimensional (3D) connected macroporosity and partially ordered mesoporosity, extremely large specific surface area, favorable graphitization degree, and high relative content of pyridinic N, which is active to the oxygen reduction reaction (ORR). Due to the combined contributions of the above features, the metal-free HPC-Ns demonstrated excellent performance in ORR with a highly comparable limiting current density but much higher current output stability and resistance towards the fuel crossover effect compared to the commercial Pt/C, as well as the dominant 4 e − reduction mechanism. Thus, it is believed that HPC-N has the potential to be used in polymer electrolyte membrane fuel cells. [ABSTRACT FROM AUTHOR]

Co-electrolysis, which can produce more than one kind of high value products concurrently at lowered energy cost, has attracted increasing attention. However, the development of novel co-electrolysis systems and efficient electro-catalysts, and the investigation of corresponding reaction mechanism, are urgently needed. Anodic biomass oxidation-coupled electrocatalytic anode/cathode hydrogen co-production has been attracting intense attentions most recently. Herein, a co-electrolysis system of α-H-armed alcohols and water has been established by introducing an efficient PdBi/NF electrocatalyst, in which hydrogen can be obtained from both anode and cathode, and alcohols can be selectively oxidized to corresponding high-value chemicals. In particular, valuable 3-Hydroxypropionic acid (3-Hp) at the anode, together with hydrogen gas at both cathode and anode, can be obtained by the co-electrolysis of water and 1, 3-propanediol (1, 3-P). More importantly, the reaction mechanism, especially the hydrogen atom and electron transfer pathway have been investigated in detail, which has been overlooked in previous literatures. [Display omitted] • A hydrogen anode/cathode co-production system coupling anode chemical synthesis. • An efficient anodic electrocatalyst PdBi/NF and electrocatalyst activation. • The detailed reaction pathway of 1, 3-P electrocatalytic conversion to 3-Hp. • Distinctive H/e transfer pathways during alcohol oxidation. [ABSTRACT FROM AUTHOR]

With a growing demand for clean and renewable energy associated with water splitting, regenerative fuel cells, metal-air batteries, etc., exploring an efficient and cost-effective electrocatalyst with superior durability for oxygen evolution reaction (OER) is of great significance. In this study, a unique CoO x embedded nanoflower microstructure (Co 0.6 -PyNa) has been synthesized via an extremely facile one-step, highly scalable aqueous method under mild conditions, by using Co(COOH) 2 as the precursor and pyrrole as the structure-directing agent. The Co 0.6 -PyNa exhibits the excellent electrocatalytic activity toward OER in 1 M KOH solution with an overpotential of as low as 299 mV and a small Tafel slope of 67 mV dec −1 , which is comparable to the commercial RuO 2 , along with superior operational stability to RuO 2 . The high OER catalytic performance of Co 0.6 -PyNa has been reasoned to originate from the exposure of abundant CoO x active species uniformly dispersed on the nanoflakes due to its high specific surface area and the intrinsic extraordinarily high activity of CoO x active species. This work provides a promising strategy to fabricate efficient, stable and low-cost OER electrocatalyst, which is expected to promote the development of OER-related energy storage and conversion technologies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Development of NiW nano–alloy as a novel HOR electro–catalyst. • The preparation process of NiW nano–alloy is facile, cost effective and scalable. • NiW nano–alloy shows much enhanced HOR catalytic activity and stability. • A possible reaction mechanism has been proposed. The efficient and low-cost electro-catalysts towards hydrogen oxidation reaction (HOR) are vitally important to the commercialization of fuel cells, which, however, have been rarely paid attentions. Herein, NiW nano-alloy electro-catalysts (∼3 nm) grown in-situ on carbon paper (NiW/CP) have been designed and synthesized by a facile and rapid (in 14 min) electro-deposition method. This alloying strategy greatly enhances the H 2 adsorption energy meanwhile reduces metal-hydrogen bonding strength on the catalyst surface, leading to the substantially lowered hydrogen oxidation energy barrier and consequently the remarkably elevated HOR catalytic activity in H 2 -saturated 0.1 M KOH electrolyte (3.26 mA cm−2 at 0.05 V vs. RHE), which is significantly higher than that of Pt/C electro-catalyst. Especially, NiW/CP shows extraordinarily high stability during 30,000 cycles and outstanding CO tolerance. Furthermore, both thermodynamic and kinetic first-principle calculations demonstrate that the HOR performance of Ni(1 1 1) can be largely enhanced by W alloying. [ABSTRACT FROM AUTHOR]