Electrocatalytic Conversion Research Articles

Plasma‐assisted fabrication of multiscale materials for electrochemical energy conversion and storage

AbstractPlasma, the fourth state of matter, is characterized by the presence of charged particles, including ions and electrons. It has been shown to induce unique physical and chemical reactions. Recently, there have been increased applications of plasma technology in the field of multiscale functional materials' preparation, with a number of interesting results. This review will begin by introducing the basic knowledge of plasma, including the definition, typical parameters, and classification of plasma setups. Following this, we will provide a comprehensive review and summary of the applications (phase conversion, doping, deposition, etching, exfoliation, and surface treatment) of plasma in common energy conversion and storage systems, such as electrocatalytic conversion of small molecules, batteries, fuel cells, and supercapacitors. This article summarizes the structure–performance relationships of electrochemical energy conversion and storage materials (ECSMs) that have been prepared or modified by plasma. It also provides an overview of the challenges and perspectives of plasma technology, which could lead to a new approach for designing and modifying electrode materials in ECSMs.

Direct low concentration CO2 electroreduction to multicarbon products via rate-determining step tuning

Direct converting low concentration CO2 in industrial exhaust gases to high-value multi-carbon products via renewable-energy-powered electrochemical catalysis provides a sustainable strategy for CO2 utilization with minimized CO2 separation and purification capital and energy cost. Nonetheless, the electrocatalytic conversion of dilute CO2 into value-added chemicals (C2+ products, e.g., ethylene) is frequently impeded by low CO2 conversion rate and weak carbon intermediates’ surface adsorption strength. Here, we fabricate a range of Cu catalysts comprising fine-tuned Cu(111)/Cu2O(111) interface boundary density crystal structures aimed at optimizing rate-determining step and decreasing the thermodynamic barriers of intermediates’ adsorption. Utilizing interface boundary engineering, we attain a Faradaic efficiency of (51.9 ± 2.8) % and a partial current density of (34.5 ± 6.4) mA·cm−2 for C2+ products at a dilute CO2 feed condition (5% CO2 v/v), comparing to the state-of-art low concentration CO2 electrolysis. In contrast to the prevailing belief that the CO2 activation step (CO2+e−+*→CO2−*\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{CO}}_{2}+{e}^{-}+\\, * \\,\ o {}^{ * }{CO}_{2}^{-}$$\\end{document}) governs the reaction rate, we discover that, under dilute CO2 feed conditions, the rate-determining step shifts to the generation of *COOH (CO2−*+H2O→C*OOH+OH−(aq)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${}^{ * } {{CO}}_{2}^{-}+{H}_{2}O\ o {}^{ * } {COOH}+{{OH}}^{-}({aq})$$\\end{document}) at the Cu0/Cu1+ interface boundary, resulting in a better C2+ production performance.

3D Pt@ZnAl-LDH catalyst on low-grade charcoal: A novel electrochemical platform for efficient textile dye degradation and glycerol oxidation

The development of sustainable and efficient electrochemical processes is crucial for addressing global challenges related to water scarcity. In this study, we present a novel 3D core-shell electrocatalyst, Pt@ZnAl-LDH, supported on low-grade charcoal (LGC), which exhibits exceptional electrocatalytic activity for the degradation and decolorization of dye and the electrocatalytic conversion of glycerol to valuable C3 chemicals. The electrocatalytic degradation of methylene blue dye from water was investigated with a focus on the impact of temperature, pH, and dye concentration. The Pt@ZnAl-LDH/LGC anode demonstrates high selectivity for converting glucose into lactate and other C3 products, achieving an impressive 85% conversion rate at 0.5 V vs. Furthermore, the electrode achieves an exceptionally high level of selectivity for C3 products, reaching 86% at 2.2 V vs, significantly outperforming other electrodes. Theoretical calculations and electrochemical in situ techniques reveal that the incorporation of ZnAl-LDH enhances the adsorption of hydroxyl species, leading to improved glucose oxidation reaction performance. The 3D Pt@ZnAl-LDH/LGC catalyst optimizes glycerol adsorption, preventing the formation of unwanted intermediates and ensuring high activity and selectivity for C3 products. This work presents a novel electrocatalytic compound for the degradation of toxic dyes and the production of valuable C3 products using an inexpensive aqueous glucose oxidation method.

Hydrogen Peroxide Electrosynthesis via Selective Oxygen Reduction Reactions Through Interfacial Reaction Microenvironment Engineering.

The electrochemical two-electron oxygen reduction reaction (2e- ORR) offers a compelling alternative for decentralized and on-site H2O2 production compared to the conventional anthraquinone process. To advance this electrosynthesis system, there is growing interest in optimizing the interfacial reaction microenvironment to boost electrocatalytic performance. This review consolidates recent advancements in reaction microenvironment engineering for the selective electrocatalytic conversion of O2 to H2O2. Starting with fundamental insights into interfacial electrocatalytic mechanisms, an overview of various strategies for constructing the favorable local reaction environment, including adjusting electrode wettability, enhancing mesoscale mass transfer, elevating local pH, incorporating electrolyte additives, and employing pulsed electrocatalysis techniques is provided. Alongside these regulation strategies, the corresponding analyses and technical remarks are also presented. Finally, a summary and outlook on critical challenges, suggesting future research directions to inspire microenvironment engineering and accelerate the practical application of H2O2 electrosynthesis is delivered.

Electroreforming of plastic wastes for value-added products.

The problem of plastic pollution is becoming increasingly serious, and there is an urgent need to reduce the use of plastics and to improve the recovery rate of plastic wastes. Plastic wastes can be transformed into value-added chemicals at the anode through electrocatalytic conversion, while coupling with cathodic reduction reactions to achieve cogeneration of valuable anodic and cathodic products. The plastic electroreforming technology has unprecedented advantages, including a green and decentralizable process, renewable energy storage, ecological benefits, resource recovery, cost-effectiveness, and so on. Herein, we present a mini review about recent advances in this topic. We first discuss the electrooxidation mechanisms of different plastic wastes (such as polylactic acid, polyethylene glycol terephthalate, polyethylene, polyethylene furanoate, polybutylene terephthalate, and polyamides). Then, the progress of plastic waste-assisted electrolysis systems is summarized, including plastic waste-assisted water splitting for hydrogen production and oxygen reduction, as well as plastic electroreforming coupled with CO2 reduction, and the nitrate reduction reaction. Finally, the development prospects and challenges in this field are introduced and discussed. This review aims to provide a concise overview of the emerging plastic electroreforming, thus offering insight on the design of efficient and stable plastic-assisted electrolysis systems.

Cation‐Vacancy Engineering Modulated Perovskite Oxide for Boosting Electrocatalytic Conversion of Polysulfides

AbstractLithium‐sulfur batteries face challenges like polysulfide shuttle and slow conversion kinetics, hindering their practical applications in renewable energy storage and electric vehicles. Herein, a solution to solve this issue is reported by using a cation vacancy engineering strategy with rational synthesis of La‐deficient LaCoO3 (LCO‐VLa). The introduction of cation vacancies in LCO‐VLa modifies the geometric structure of coordinating atoms, exposing Co‐rich surface with more catalytically active surfaces. Meanwhile, the d‐band center of LCO‐VLa shifts toward the Fermi level, enhancing polysulfide adsorption. Furthermore, multivalent cobalt ions (Co3+/Co4+) induced by charge compensation enhance the electrical conductivity of LCO‐VLa, accelerating electron transfer processes and improving catalytic performance. Theoretical calculations and experimental characterizations demonstrate that La‐deficient LCO‐VLa effectively suppresses the polysulfide shuttle, reduces the energy barrier for polysulfide conversion, and accelerates redox reaction kinetics. LCO‐VLa‐based batteries demonstrate exceptional rate performance and cycling stability, retaining 70% capacity after nearly 500 cycles at 1.0 C, with a minimal decay rate of 0.055% per cycle. These findings highlight the significance of cation vacancy engineering for exploring precise structure‐activity relationships during polysulfides conversion, facilitating the rational design of catalysts at the atomic level for lithium‐sulfur batteries.

Achieving Market-Ready Economic and Environmental Feasibility of Biomass-Based Plastic, Polyethylene Furanoate (PEF), via Electrocatalytic Conversion of Crude 5-Hydroxymethyfurfural (HMF) Solution

Polyethylene furanoate (PEF) has excellent physicochemical properties among biomass-derived plastics, and its applications are expanding beyond food and beverage packaging to textiles, films, and 3D printings. Nevertheless, commercialized large-scale production of PEF has yet to be accomplished due to the high cost of FDCA (2,5-furan dicarboxylic acid), the monomer of PEF. FDCA is synthesized via selective carboxylation of 5-hydroxymethyl furfural (HMF), and the use of high purity HMF (>99%) is essential to obtain polymerizable purity of FDCA. HMF is synthesized by strong acid saccharification and dehydration/isomerization of cellulose, and various by-products and unreacted sugars coexist during the synthesis process. Consequently, the purification and separation process is necessary to obtain the high-purity HMF, which significantly increases the production cost. In this presentation, I present the electrochemical production of high-purity FDCA from unrefined HMF solution, which is about 8 times cheaper than 99% HMF, without a purification process. The techno-economic analysis (TEA) life-cycle assessment (LCA) analyses demonstrate that the electrochemical synthesis of FDCA from crude feedstock not only makes it cheaper than a thermochemical process that can only utilize high-purity HMF, but also significantly reduces carbon emissions. In addition, the principle of the electrocatalysis that selectively converts HMF to FDCA while harmlessly removing impurities from the unrefined HMF solution was investigated by in-situ/operando X-ray absorption spectroscopy (XAS) and attenuated total reflection-Fourier transform Infrared Spectrometer (ATR-FTIR) analyses.

Phase-dependent photo-assisted electrocatalytic conversion of nitrate to ammonia using TiO2: Insights into amorphous and rutile activity

The rise in nitrogen-containing compounds in water sources due to modern agricultural practices has intensified the need to effectively convert nitrate to ammonia, a valuable fertiliser and fuel. We developed a photo-assisted electrocatalytic system using a NiO/Au plasmon/TiO2 composite to selectively reduce nitrate to ammonia under visible light, at neutral pH, and at room temperature. TiO2 was found to be the active catalyst, but the precise active structure responsible for each catalytic step remains unclear, as the reaction involves a complex, multistep process. By analyzing the catalytic activity of different TiO2 phases, we found that amorphous TiO2 significantly enhances the nitrate-to-nitrite reduction step, increasing nitrite concentration in solution by nearly 50 % and resulting in a 10 % increase in Faradaic efficiency for this product. Conversely, the rutile phase plays a crucial role in the subsequent conversion of nitrite to ammonia. When the rutile phase was present, the ammonia yield more than doubled, leading to a 30 % increase in Faradaic efficiency. This phase-dependent behaviour provides critical insights into improving nitrate reduction efficiency, enabling sustainable agricultural practices that recycle nutrients, reduce fertiliser costs, and promote economic sustainability.

Isolated Rhodium Atoms Activate Porous TiO2 for Enhanced Electrocatalytic Conversion of Nitrate to Ammonia.

The direct electrochemical reduction of nitrate to ammonia is an efficient and environmentally friendly technology, however, developing electrocatalysts with high activity and selectivity remains a great challenge. Single-atom catalysts demonstrate unique properties and exceptional performance across a range of catalytic reactions, especially those that encompass multi-step processes. Herein, a straightforward and cost-effective approach is introduced for synthesizing single-atom dispersed Rh on porous TiO2 spheres (Rh1-TiO2), which functions as an efficient electrocatalyst for the electroreduction of NO3 - to NH3. The synthesized Rh1-TiO2 catalyst achieve a maximum NH3 Faradaic efficiency (FE) of 94.7% and an NH3 yield rate of 29.98mgh-1 mgcat -1 at -0.5V versus RHE in a 0.1MKOH+0.1MKNO3 electrolyte, significantly outperforming not only undoped TiO2 but also Ru, Pd, and Ir single-atom doped titania catalysts. Density functional theory calculations reveal that the incorporation of Rh single atom significantly enhances charge transfer between adsorbed NO3 - and the active site. The Rh atoms not only serve as the highly active site for electrochemical nitrate reduction reaction (NO3RR), but also activates the adjacent Ti sites through optimizating the electronic structure, thereby reducing the energy barrier of the rate-limiting step. Consequently, this results in a substantial enhancement in electrochemical NO3RR performance. Furthermore, this synthetic method has the potential to be extended to other single-atom catalysts and scaled up for commercial applications.

Trimetallic FeNiCo layered double hydroxide catalysts for industrial-level electrochemical glycerol upgrading

Electrocatalytic conversion of glycerol, a byproduct of biodiesel production, into high value-added chemicals presents a transformative approach for biomass valorization. However, developing stable catalysts that consistently achieve industrial-grade current density at low potentials remains challenging. Herein, a highly efficient FeNiCo-Co(OH)2 electrocatalyst for the glycerol oxidation, by leveraging interconnected FeNiCo layered double hydroxide (LDH) nanosheets grown on a Co(OH)2 precursor is developed. This catalyst achieves an impressive current density of 1000 mA cm−2 at a low voltage of 1.38 V, exhibiting remarkable selectivity for formate and glycollate production. This superior performance stems from the optimized electronic structure and synergistic interactions within the FeNiCo LDHs, enabling the formation of high-valent species at lower potentials, efficient handling reaction intermediates, reduced charge transfer resistance, upward d band center and optimized mass transport, thereby enhancing glycerol adsorption and oxidation. Notably, the electrode exhibits stable operation at 120 mA cm−2 for 32 h and yields 227.50 and 104.17 mmol cm−2 for formate and glycollate, respectively, at industrial current densities for 8 h. This study unveils a novel transition metal-based glycerol oxidation reaction electrocatalyst and lays a foundation for its industrial application, highlighting significant advancements in biomass valorization.

Adsorbate Resonance Induces Water-Metal Bonds in Electrochemical Interfaces.

This study delves into the intricate interactions between surface-near species, OH and H2O, on electrodes in electrochemical interfaces. These species are an inevitable part of many electrocatalytic energy conversion reactions such as the oxygen reduction reaction. In our modeling, we utilize high statistics on a dataset of complex solid solutions with high atomic variability to show the emergence of H2O-metal covalent bonds under specific conditions. Based on density functional theory (DFT) calculations ofadsorption energies onmany thousands of different surface compositions, we provide a quantifiable physical understanding of this induced water covalency, which is rooted in simple quantum mechanics. Directional hydrogen bonding between surface-near H2O and OH, enables surface bonding electrons to delocalize mediatedby near-symmetrical adsorbate resonance structures. The different adsorbate resonance structures differ by surface coordination explaining the induced H2O-metal bonding.

Adsorbate Resonance Induces Water‐Metal Bonds in Electrochemical Interfaces

AbstractThis study delves into the intricate interactions between surface‐near species, OH and H2O, on electrodes in electrochemical interfaces. These species are an inevitable part of many electrocatalytic energy conversion reactions such as the oxygen reduction reaction. In our modeling, we utilize high statistics on a dataset of complex solid solutions with high atomic variability to show the emergence of H2O‐metal covalent bonds under specific conditions. Based on density functional theory (DFT) calculations of adsorption energies on many thousands of different surface compositions, we provide a quantifiable physical understanding of this induced water covalency, which is rooted in simple quantum mechanics. Directional hydrogen bonding between surface‐near H2O and OH, enables surface bonding electrons to delocalize, mediated by near‐symmetrical adsorbate resonance structures. The different adsorbate resonance structures differ by surface coordination explaining the induced H2O‐metal bonding.

Unveiling the Structural Effects in Hybrid Copper Phosphonate Frameworks for Selective Electrocatalytic CO2 Reduction Reaction.

Electrochemical CO2 reduction holds tremendous promise for transforming carbon dioxide into several value-added energy feedstocks and utilizing renewable energy sources. Herein, we have developed two novel copper-based organophosphonates for selective electrocatalytic conversion of CO2 to CH3OH conversion. The two-dimensional layer structure of Cu3[(Hhedp)2(C4H4N2)].2H2O (I) and the three-dimensional Cu3[(H3hedp)2(C4H4N2)4(SO4)].2H2O (II) have been isolated as single crystals via a hydrothermal strategy. Compound I consists of Cu2+ oxidation states exclusively, while compound II has Cu1+ oxidation states in a network wherein a Cu2+-phosphonate template is embedded inside the framework. Depending on mixed valent oxidation states, compound II exhibits high selectivity compared to compound I for the electrocatalytic reduction of CO2 to CH3OH (C1) as the primary product and CH3COOH (C2) as the secondary product. Notably, product selectivity is enhanced as the Faradaic efficiency (FE) of the competing hydrogen evolution reaction (HER) is significantly reduced in compound II relative to that of I, particularly at higher applied reduction potentials. The optimal ratio of Cu1+ active sites in compound II plays a pivotal role in enhancing methanol selectivity, stabilizing critical intermediates, and maintaining ideal reduction potentials as a noble-metal free electrocatalyst. Moreover, the optical band gap and the Mott-Schottky measurements further suggest the title Cu-phosphonate materials could be promising and effective photocatalysts.

Greener Production and Application of Slow-Release Nitrogen Fertilizer Using Plasma and Nanotechnology: A Review

The potential of both plasma and nanotechnology in producing slow-release fertilizer is immense. These technologies, when combined, may offer green and inexpensive nitrogen fertilizers, from rich renewable resources available in local areas. Together, these technologies may overcome some limitations of conventional synthetic fertilizers, which are currently expensive and associated with low nitrogen use efficiency and significant environmental concerns. This review explores the utilization of recent advances in plasma and nanotechnology, which can be leveraged to create new slow-release nitrogen fertilizers. It emphasizes their crucial role in addressing nitrogen depletion and improving crop production. Despite the lack of attempts to develop slow-release nanofertilizers from low-cost liquid nitrate generated by emission-free nonthermal plasma, the effectiveness of plasma nitrate matches that of conventional fertilizer for crop production. We propose a more efficient electrocatalytic conversion of plasma nitrate to ammonium salt, then coating it with plant-based cellulose nanoparticles to create a slow-release form. This set of processes would synchronize nutrient release with the dynamic N requirements of plants. Formulations using agro-based, low-cost cellulose nanomaterials could replace high-cost carrier hydrogels associated with low mechanical strength. This review also highlights the isolation of nanocellulose from various plant materials and its characterization in different formulations of slow-release nanoplasma N fertilizer. Additionally, we discuss mechanisms of N loss, slow-release, and retention in the soil that can contribute to the production and use of efficient, sustainable fertilizers to improve food security and, consequently, the health of our planet.

Selenic Acid Etching Assisted Atomic Engineering for Designing Metal-Semimetal Dual Single-Atom Catalysts for Enhanced CO2 Electroreduction.

Single-atom catalysts are promising for electrocatalytic CO2 conversion but face challenges in controllable syntheses. Herein, a facile selenic acid etching-assisted strategy has been developed to fabricate a hybrid metal-semimetal dual single-atom catalyst for electrocatalytic CO2 reduction. This strategy enables the simultaneous generation of monodisperse active sites and hierarchical morphologies with hollow nanostructures. The as-obtained catalyst with Fe-Se dual single-atom sites supported by porous nitrogen-doped carbon (FeSe-NC) shows exceptional catalytic activity and CO selectivity, delivering a Faradaic efficiency (FE) of >97% with industrially comparable jCO, superior to the Fe single-atom catalyst. Moreover, the FeSe-NC-based rechargeable Zn-CO2 battery delivers a high power density (2.01 mW cm-2) and outstanding FECO (>90%), as well as excellent cycling stability. Experimental results together with theoretical calculations reveal that the etching-induced defects and the Se-modulated Fe centers with asymmetrical polarized charge distributions synergistically facilitate the key intermediate *CO desorption and thus accelerate the CO2-to-CO conversion.

Exploring interfacial electrocatalysis for iodine redox conversion in zinc-iodine battery

The challenges posed by the non-conductive nature of iodine, coupled with the easy formation of soluble polyiodides in water, impede its integration with zinc for the development of advanced rechargeable batteries. Here we demonstrate the in-situ loading of molybdenum carbide nanoclusters (MoC) and zinc single atoms (Zn-SA) into porous carbon fibers to invoke electrocatalytic conversion of iodine at the interface. The electronic interactions between MoC and Zn-SA lead to an upshift in the d-band center of Mo relative to the Fermi level, thus promoting the interfacial interactions with iodine species to suppress shuttle effects. Notably, the optimal charge delocalization, induced by d-p orbital hybridization between molybdenum and iodine, also lowers the redox energy barrier to promote the interfacial conversion. With interfacial electrocatalysis minimizing polyiodide intermediates via a favorable redox conversion pathway, zinc-iodine batteries therefore demonstrate a large specific capacity of 230.6 mAh g−1 and the good capacity retention for 20,000 cycles.

Enhanced electrocatalytic C[sbnd]H amination of toluene via tailored interfacial microenvironment

Electrocatalytic CH amination of hydrocarbons is a promising avenue for the synthesis of high-value CN compounds. However, efficient activation of CH bonds remains a significant challenge in electrocatalytic CN coupling. Herein, we present a novel strategy to enhance the electrocatalytic conversion of toluene to N-benzylacetamide through a Ritter–type reaction by engineering a hydrophobic electrode–electrolyte interface using polytetrafluoroethylene (PTFE)-coated carbon paper (CP). The hydrophobic CP-based electrode exhibited a superior N-benzylacetamide productivity of 1860.9 mmol m−2h−1 and a substantially higher Faradaic efficiency (FE) of 70.1 % compared to pure CP (41.5 %). Experimental results and density functional theory (DFT) calculations reveal that the PTFE coating promotes toluene adsorption and efficiently lowers the energy barrier for toluene dehydrogenation. Additionally, the hydrophobic interface effectively hinders water adsorption on the electrode, suppressing the competitive water oxidation reaction. This study underscores the crucial role of interfacial engineering in optimizing electrocatalytic CN coupling reactions for the sustainable synthesis of high-value amide compounds.

Electrochemical and Non-Electrochemical Pathways in the Electrocatalytic Oxidation of Monosaccharides and Related Sugar Alcohols into Valuable Products.

In this contribution, we review the electrochemical upgrading of saccharides (e.g., glucose) and sugar alcohols (e.g., glycerol) on metal and metal-oxide electrodes by drawing conclusions on common trends and differences between these two important classes of biobased compounds. For this purpose, we critically review the literature on the electrocatalytic oxidation of saccharides and sugar alcohols, seeking trends in the effect of reaction conditions and electrocatalyst design on the selectivity for the oxidation of specific functional groups toward value-added compounds. Importantly, we highlight and discuss the competition between electrochemical and non-electrochemical pathways. This is a crucial and yet often neglected aspect that should be taken into account and optimized for achieving the efficient electrocatalytic conversion of monosaccharides and related sugar alcohols into valuable products, which is a target of growing interest in the context of the electrification of the chemical industry combined with the utilization of renewable feedstock.

Electrochemical Oxidation of Low-Concentration Methane on Pt/Pt and Pt/CP under Ambient Conditions.

Methane is a potent greenhouse gas, and its rapid conversion at low concentrations under ambient conditions is a challenging process where combustion is not an option. Herein, we report an electrochemical method to address this problem. It was achieved by applying an oxidation potential to electrochemically activate methane followed by conducting an anodic cyclic voltammogram to fully oxidize activated methane to carbon dioxide on platinized Pt mesh (Pt/Pt) and carbon paper (Pt/CP). This "dynamic potential" oxidation approach enabled methane conversion with low energy consumption, thanks to the low activation potential. Effects of various experimental conditions (applied potential, reaction time, and methane concentration) were investigated. Pure methane and methane/nitrogen gas mixtures containing a series of low concentrations of methane were tested. It was found that methane conversion is independent of its concentration on both Pt/Pt and Pt/CP. Compared to Pt/Pt electrocatalysis, Pt/CP displayed approximately 10 times higher catalytic activity, which can be attributed to the stronger binding of intermediate CO* to Pt, leading to easier CO* activation in the presence of a carbon substrate. Carbon dioxide was the only compound detected during the electro-oxidation phase for Pt/Pt, while for Pt/CP, carbon dioxide and a small amount of formic acid (after 15 h reaction) were observed. Electrocatalytic conversion of methane to carbon dioxide on Pt/CP using 0.5% methane was measured, giving a methane conversion rate of 7.5 × 10-8 mol L-1 s-1 m-2, while the methane conversion rate on Pt/Pt with 1% methane was only 8.3 × 10-9 mol L-1 s-1 m-2.

Unconventional Electrocatalytic CO Conversion to C2 Products on Single-Atomic Pd-Agn Sites.

The electrochemical reduction of CO or CO2 into C2+ products has mostly been focused on Cu-based catalysts. Although Ag has also been predicted as a possible catalyst for the CO-to-C2+ conversion from the thermodynamic point of view, however, due to its weak CO binding strength, CO rapidly desorbs from the Ag surface rather than participates in deep reduction. In this work, we demonstrate that single-atomic Pd sites doped in Ag lattice can tune the CO adsorption behavior and promote the deep reduction of CO toward C2 products. The monodispersed Pd-Agn sites enable the CO adsorption with both Pd-atop (PdL) and Pd-Ag bridge (PdAgB) configurations, which can increase the CO coverage and reduce the C-C coupling energy barrier. Under room temperature and ambient pressure, the Pd1Ag10 alloy catalyst exhibited a total CO-to-C2 Faradaic efficiency of ~37 % at -0.83 V, with appreciable current densities and electrochemical stability, thus featuring unconventional non-Cu electrocatalytic CO-to-C2 conversion capability.