Electrocatalytic Oxidation Of Ethanol Research Articles

OH Regulator of Amorphous CrOx on Defect-Rich Ultrafine Pd Nanowires Boosts Electrocatalytic Ethanol Oxidation.

Reasonable construction of high activity and selectivity electrocatalysts is crucial to achieve efficient ethanol oxidation reaction (EOR). However, the oxidation of ethanol tends to produce CO species that poison the active centers of the EOR electrocatalysts. Herein, a unique amorphous CrOx-protected defect-rich ultrafine Pd nanowires (CrOx-Pd NWs) is developed. On the one hand, the CrOx layer can act as a protective layer to maintain the structure of the nanowire. On the other hand, it can play the role of OH regulator to optimize the adsorption energy barrier of intermediate species in Pd nanowire, thereby enhancing the ability of the catalyst to resist CO poisoning. The CrOx-Pd NWs exhibit excellent EOR performance with 3.64 times higher mass activity and 50mV lower CO electro-oxidation potential than commercial Pd black. The results show that the CrOx layer promotes the dissociation of H2O into OHads, while the CrOx transfers electrons to neighboring Pd atoms optimizing the electronic configuration of Pd, thus selectively oxidizing ethanol to acetate and preventing the formation of toxic *CO. This work provides an effective strategy for the synthesis of nanowire materials with oxide/metal interfaces and offers new ideas for the design of catalysts that can efficiently drive EOR.

Kinetic Understanding of Metal Ions Doping in Enhancing the Electrocatalytic Ethanol Oxidation Performance of Nickel Hydroxides

Kinetic Understanding of Metal Ions Doping in Enhancing the Electrocatalytic Ethanol Oxidation Performance of Nickel Hydroxides

Empowering Tri-Functional Palladium's Catalytic Activity and Durability in Electrocatalytic Formic Acid Oxidation Reaction via Innovative Self-Caging and Alloying Strategies.

Direct formic acid fuel cells (DFAFCs) stand out for portable electronic devices owing to their ease of handling, abundant fuel availability, and high theoretical open circuit potential. However, the practical application of DFAFCs is hindered by the unsatisfactory performance of electrocatalysts for the sluggish anodic formic acid oxidation reaction (FAOR). Palladium (Pd) based nanomaterials have shown promise for FAOR due to their highly selective reaction mechanism, but maintaining high electrocatalytic durability remains challenging. In this study, a novel Pd-based electrocatalyst (UiO-Pd-E) is reported with exceptional durability and activity for FAOR, which can be attributed to the Pd nanoparticles encapsulated within a carbon framework where concurrent chemical alloying of Pd and Zr occurs. Further, the UiO-Pd-E demonstrates noteworthy multifunctionality in various electrochemical reactions including electrocatalytic ethanol oxidation reaction (EOR) and oxygen reduction reaction (ORR) in addition to the FAOR, highlighting its practical potentials.

Construction of Multiphase Concave Tetrahedral PdInMo Nanocatalyst for Enhanced Alcohol Oxidation

AbstractHeterogeneous palladium‐based catalysts show excellent catalytic properties for electrocatalytic oxidation of alcohols, but the construction of such heterogeneous catalysts is a challenge. Here, a multiphase tetrahedral PdInMo nanocatalyst is prepared by a one‐pot reaction method. And the multiphase tetrahedral PdInMo nanocatalyst consists of a face‐centered cubic structure and an intermetallic structure. Due to the oxygen affinity of indium and molybdenum atoms, the interface defects of internal multiphase structure, and intermetallic structure, the multiphase concave tetrahedral PdInMo nanocatalyst shows enhanced catalytic efficiency in the electrocatalytic oxidation reaction of methanol and ethanol. Compared with commercial Pd/C catalysts, PdIn0.117Mo0.037 nanocatalyst has the best mass activity and specific activity. In electrocatalysis of methanol oxidation, the mass activity (2205.57 mA mgPd−1) and specific activity (6.67 mA cm−2) are 4.81 and 3.40 times than that of a commercial Pd/C nanocatalyst (458.5 mA mgPd−1, 1.96 mA cm−2), respectively. In the electrocatalysis of ethanol oxidation, the mass activity (2668.49 mA mgPd−1) and specific activity (8.11 mA cm−2) are 4.06 and 3.14 times than that of the commercial Pd/C nanocatalyst (655.83 mA mgPd−1, 2.58 mA cm−2), respectively. This study provides a reference for the design of highly efficient palladium catalysts for alcohol oxidation.

PtCu-a-SnO2 interface engineering on PtCu-SnO2 aerogels for ethanol oxidation electrocatalysis

Designing catalysts with high activity and stability to boost their ethanol oxidation reaction (EOR) performance is one of the central targets in the development of direct ethanol fuel cells (DEFCs). However, how to design the EOR catalysts in a rational way is still challenging, needing more efforts put in. Herein, we have synthesized a catalyst of PtCu-SnO2 aerogel via ingeniously introducing Cu into Pt-SnO2 system, resulting in the formation of a main phase of alloy (PtCu)-amorphous oxide (a-SnO2) interface. Benefiting from the optimized structures, the PtCu-SnO2 aerogel displays excellent acidic EOR performance with 4.5 times promotion in activity compared to pure Pt aerogel. In-depth investigations through electrochemical in-situ Fourier transform infrared spectroscopy and density functional theory calculations have shown that the absorbed OH on a-SnO2 surface together with the greatly-modified electronic structure of the alloy surface atoms can facilitate the C1 pathway and the oxidation of *CO intermediates for ethanol oxidation reaction. The resulting affinity of surface OH and the modification of reaction energies both in turn contribute to the improvement of EOR performance with high activity, stability, and anti-poisoning ability, proving interfacial engineering an effective strategy for the rational design of EOR catalyst.

Competitive intermetallics formation in Pd-Zn-Cd system via seeded growth from ultra-thin Pd nanosheets for electrocatalytic ethanol oxidation reaction

Competitive intermetallics formation in Pd-Zn-Cd system via seeded growth from ultra-thin Pd nanosheets for electrocatalytic ethanol oxidation reaction

Optimized Electrodeposition of Ni2O3 on Carbon Paper for Enhanced Electrocatalytic Oxidation of Ethanol.

The urgent need for sustainable and efficient energy conversion technologies has propelled research into novel electrocatalysts for fuel cell applications. This study investigates a carbon paper (CP)-supported Ni2O3 catalyst for the electrocatalytic oxidation of ethanol. We utilized electrodeposition to uniformly deposit/dop Ni2O3 onto the CP, creating an effective electrocatalyst. Our approach allows the tailoring of the doping degree by adjusting the electrodeposition potential. The optimal doping degree, achieved at a medium deposition potential, results in an electrode with high intrinsic activity and a substantial electrochemically active surface area (ECSA), thereby enhancing its electrocatalytic activity. This catalyst efficiently facilitates the oxidation of ethanol to formic acid while maintaining good stability. The enhanced performance is attributed to the effective interface and interaction between Ni2O3 and CP. This work not only provides insights into the design of efficient Ni-based catalysts for ethanol oxidation but also paves the way for developing advanced materials for renewable energy conversion.

Candle Soot as a Novel Support for Nickel Nanoparticles in the Electrocatalytic Ethanol Oxidation.

The enhancement of carbon-supported components is a crucial factor in augmenting the interplay between carbon-supported and metal-active components in the utilization of catalysts for direct ethanol fuel cells (DEFCs). Here, we propose a strategy for designing a catalyst by modifying candle soot (CS) and loading nickel onto ordered carbon soot. The present study aimed to investigate the effect of the Ni nanoparticles content on the electrocatalytic performance of Ni-CS, ultimately leading to the identification of a maximum composition. The presence of an excessive quantity of nickel particles leads to a decrease in the number of active sites within the material, resulting in sluggishness of the electron transfer pathway. The electrocatalyst composed of nickel and carbon support, with a nickel content of 20 wt%, has demonstrated a noteworthy current activity of 18.43 mA/cm2, which is three times that of the electrocatalyst with a higher nickel content of 25 wt%. For example, the 20 wt% Ni-CS electrocatalytic activity was found to be good, and it was approximately four times higher than that of 20 wt% Ni-CB (nickel-carbon black). Moreover, the chronoamperometry (CA) test demonstrated a reduction in current activity of merely 65.80% for a 20 wt% Ni-CS electrocatalyst, indicating electrochemical stability. In addition, this demonstrates the great potential of candle soot with Ni nanoparticles to be used as a catalyst in practical applications.

Toward Developing Superior Cu-Based Metal-Organic Framework-Derived Materials for Electrocatalytic Oxidation of Ethanol.

This project addresses the urgent need for efficient and cost-effective development of electrocatalysts for the ethanol oxidation reaction (EOR). This reaction offers promising renewable energy solutions but faces challenges due to the slow EOR kinetics, typically requiring costly noble metal catalysts. To overcome these limitations, this study focuses on developing CuZn-based EOR catalysts derived from metal-organic frameworks (MOFs), focusing on understanding the structure-performance relationship between pristine MOF-based electrocatalysts and their pyrolyzed counterparts. Herein, bimetallic MOF materials with varying Cu/Zn ratios were synthesized, followed by pyrolysis to produce carbonized counterparts while preserving the fundamental structure but with altered physicochemical properties. Comparative EOR studies revealed the superior performance of pyrolyzed MOFs, demonstrating that optimized Zn-loading is crucial over Cu-based framework for catalyst performance and durability. Overall, this work highlights the potential of MOF-derived Cu-based catalysts for renewable energy applications and provides insights into optimizing their performance through controlled synthesis and post-treatment strategies.

Bioelectrocatalytic Activity of One-Dimensional Porous Pt Nanoribbons for Efficient Inhibition of Tumor Growth and Metastasis.

Designing and synthesizing one-dimensional porous Pt nanocrystals with unique optical, electrocatalytic, and theranostic properties are gaining lots of attention, especially to overcome the challenges of tumor recurrence and resistance to platinum-based chemotherapy. Herein, we represented an interesting report of a one-step and facile strategy for synthesizing multifunctional one-dimensional (1D) porous Pt nanoribbons (PtNRBs) with highly efficient therapeutic effects on cancer cells based on inherent electrocatalytic activity. The critical point in the formation of luminescent porous PtNRBs was the use of human hemoglobin (Hb) as a shape-regulating, stabilizing, and reducing agent with facet-specific domains on which fluorescent platinum nanoclusters at first are aggregated by aggregation-induced emission phenomena (AIE) and then crystallized into contact and penetration twins, as intermediate products, followed by shaping of the final luminescent porous ribbon nanomaterials, owing to oriented attachment association via the Ostwald ripening mechanism. From a medical point of view, the key strategy for effective cancer therapy occured via using low-dosage ethanol in the presence of electroactive porous PtNRBs based on intracellular ethanol oxidation-mediated reactive oxygen species (ROS) generation. The role of heme groups of Hb, as electrocatalytically active centers, was successfully demonstrated in both kinetically controlled anisotropic growth of NRBs for slowing down the reduction of Pt(II) followed by oligomerization of Pt(II)-Hb complexes via platinophilic interactions as well as electrocatalytic ethanol oxidation for therapy. Interestingly, hyaluronic acid-targeted (HA) Hb-PtNRB in the presence of low-dose ethanol caused extraordinary arrest of tumor growth and metastasis with no recurrence even after the treatment course stopped, which caused elongation of tumor-bearing mice survival. HA/Hb-PtNRB was completely biocompatible and exhibited high tumor-targeting efficacy for fluorescent imaging of breast tumors. Therefore, the synergistic electrocatalytic activity of PtNRBs is presented as an efficient and safe cancer theranostic method for the first time.

Local coordination and electronic interactions of Pd/MXene via dual‐atom codoping with superior durability for efficient electrocatalytic ethanol oxidation

AbstractCatalyst design relies heavily on electronic metal‐support interactions, but the metal‐support interface with an uncontrollable electronic or coordination environment makes it challenging. Herein, we outline a promising approach for the rational design of catalysts involving heteroatoms as anchors for Pd nanoparticles for ethanol oxidation reaction (EOR) catalysis. The doped B and N atoms from dimethylamine borane (DB) occupy the position of the Ti3C2 lattice to anchor the supported Pd nanoparticles. The electrons transfer from the support to B atoms, and then to the metal Pd to form a stable electronic center. A strong electronic interaction can be produced and the d‐band center can be shifted down, driving Pd into the dominant metallic state and making Pd nanoparticles deposit uniformly on the support. As‐obtained Pd/DB–Ti3C2 exhibits superior durability to its counterpart (∼14.6% retention) with 91.1% retention after 2000 cycles, placing it among the top single metal anodic catalysts. Further, in situ Raman and density functional theory computations confirm that Pd/DB–Ti3C2 is capable of dehydrogenating ethanol at low reaction energies.

Rational modulation of electronic structure in PtAuCuNi alloys boosts efficient electrocatalytic ethanol oxidation assisted with energy-saving hydrogen evolution

Compared to conventional electrocatalytic water splitting, electrocatalytic ethanol oxidation reaction (EOR) along with hydrogen production is considered a more energy-efficient strategy. Herein, we prepared a type of novel quaternary alloy catalyst (PtAuCuNi@NF) that exhibits excellent activity for EOR (0.215 V at 10 mA cm−2) and hydrogen evolution reaction (HER) (7 mV at 10 mA cm−2). Experimental results demonstrated that both Cu and Ni modulated the electronic environment around Pt and Au. The electron-rich active center facilitates the rapid adsorption and dissociation of reactants and intermediates for both EOR and HER. Impressively, in the ethanol-assisted overall water splitting (E-OWS), a current density of 10 mA cm−2 was achieved at 0.28 V. Moreover, an advanced acid-base self-powered system (A-Bsps) that can achieve a self-powered voltage of 0.59 V was assembled. Accordingly, the self-driven hydrogen production with zero external power supply was realized by integrating A-Bsps with the E-OWS equipment. The interesting results can provide a feasible strategy for designing and developing advanced nanoalloy-based materials for clean energy integration and use in various fields.

Wet‐Chemical Epitaxial Growth of Metastable‐Phase Intermetallic Electrocatalysts

AbstractMetastable‐phase intermetallic compounds (IMCs) provide great flexibility to modify the electronic structure and surface coordination environment of metallic catalysts for various reactions. However, the synthesis of metastable‐phase IMCs with high catalytic performance remains a great challenge due to their thermodynamically unstable nature. Here, a wet‐chemical epitaxial growth strategy to synthesize metastable‐phase Pd‐Bi intermetallic nanocrystals (NCs) is reported. β‐Pd3Bi and γ‐Pd5Bi3 intermetallic NCs are epitaxially grown on the templates of face‐centered cubic Pd3Pb nanocubes and hexagonal close‐packed PtBi nanoplates, achieving Pd3Pb@Pd3Bi and PtBi@Pd5Bi3 core–shell NCs, respectively. The obtained Pd3Pb@Pd3Bi NCs possess a mass activity and specific activity of 8.52 A mg−1Pd and 11.59 mA cm−2 for ethanol oxidation reaction, which is 7.5 and 3.6 times as high as those of commercial Pd/C, respectively. Meanwhile, Pd3Pb@Pd3Bi NCs possess superior stability than commercial Pd/C. This work advances the design and synthesis of high‐performance metastable‐phase IMCs, opening an avenue for electrocatalytic ethanol oxidation and beyond.

Strain effect induced Pd nanoparticles decorated Pd2+-doped Co3O4 nanosheets for efficient electrocatalytic ethanol oxidation and oxygen reduction reactions

Reactive metal-support interaction (RMSI) is an effective means of inducing surface strain and charge transfer in catalysts, which further enhances electrochemical activity and modulates reaction pathways. Nevertheless, the precise synthesis of nanomaterials with tunable strain and unique morphology remains a challenge. In this work, we have synthesized Pd nanoparticles decorated Pd2+- doped Co3O4 nanosheets (Pd7.4%/Co3O4) by a NaBH4 reduction method, which exhibit excellent performance for ethanol oxidation reaction (EOR) and oxygen reduction reaction (ORR). The introduction of the Pd into the Co3O4 by the means of elemental doping and nanoparticle decoration, and the resulting lattice strain and electron redistribution are responsible for the improved performance. Meanwhile, Pd7.4%/Co3O4 has a relatively low d-band center that reduces the adsorption energy of reaction intermediates to improve reaction selectivity and eliminate EOR toxic intermediates, ultimately promoting reaction kinetics. This work demonstrates a simple and effective strategy to manipulate lattice strain and electronic coupling and provides a novel and advanced way for the development of low-cost and high-quality direct ethanol fuel cells (DEFCs) catalysts.

Electrocatalytic Oxidation of Methanol and Ethanol with 3d-Metal Based Anodic Electrocatalysts in Alkaline Media Using Carbon Based Electrode Assembly.

Homogeneous electrocatalytic systems based on readily available, earth-abundant, inexpensive base metals Ni, Co, and Cr have been formulated for the electro-oxidation of alcohols (methanol and ethanol) that constitute a key half-cell component of direct alcohol fuel cells (DAFCs). Notably, excellent results were obtained for both methanol as well as ethanol electro-oxidation while operating with a half-cell assembly based on all-non-noble working and counter electrode systems consisting of glassy carbon and graphite rod, respectively. Using NaOH as the supporting electrolyte, Ni/Co/Cr metal salts and their bis(iminopyridine) complexes have been used as anodic electrocatalysts for the alcohol half-cell reactions, and among them, catalytic systems based on Co outperformed the corresponding systems based on Ni and Cr. The system comprising CoCl2.·6H2O [10 mM] + NaOH [6 M] at room temperature emerged as the best electrocatalyst for both methanol [5 M] electro-oxidation (ca. 522.5 ± 13.5 mA cm-2 at 1.4 V) and ethanol [5 M] electro-oxidation (ca. 209 ± 25 mA cm-2 at 1.34 V). It was observed that regardless of the starting alcohol, the end product is carbon dioxide, all of which gets trapped as sodium carbonate (up to 97% yield), thereby mitigating any possible hazards of greenhouse gas emission. Inferences obtained from FETEM, FESEM, and EDS analysis of both the electrolyte solution and residues deposited on the electrode surface provide evidence for the mostly homogeneous nature of the reaction mixture with the molecular catalyst being the major contributor toward the electrocatalytic activity apart from the minor role played by trace heterogeneous particles. The current cell assembly operating with non-noble working and counter electrodes utilizing a catalytic system based on an earth-abundant, base metal salt/complex that not only results in good half-cell current densities for high-energy power-source DAFCs but also generates high-value sodium carbonate offers an exciting avenue.

2D petal-like PdAg nanosheets promote efficient electrocatalytic oxidation of ethanol and methanol.

The development of efficient alcohol electrooxidation catalysts is of vital importance for the commercialization of direct liquid fuel cells. As emerging advanced catalysts, two-dimensional (2D) noble metal nanomaterials have attracted much research attention due to their intrinsic structural advantages. Herein, we report the synthesis of petal-like PdAg nanosheets (NSs) with an ultrathin 2D structure and jagged edges via a facile wet-chemical approach, combining doping engineering and morphology tuning. Notably, the highly active sites and Pd-Ag composition endowed PdAg NSs with improved toxicity tolerance and substantially improved the durability toward the ethanol/methanol oxidation reaction (EOR/MOR). Moreover, the electronic effect and synergistic effect significantly enhanced the EOR and MOR activities in comparison with Pd NSs and commercial Pd/C. This work provides efficient catalysts for fuel electrooxidations and deep insight into the rational design and fabrication of novel 2D nanoarchitecture.

One-pot synthesis of PdAuAg nanocrystals for efficient electrocatalytic oxidation of ethanol: achieving morphology control by independently adjusting metal-atom concentrations

Versatile morphology control over PdAuAg nanocrystals is realized by introducing the three metallic precursor solutions at independently-controlled rates, which exhibit exceptional performance as EOR electrocatalysts.

High-entropy PtCuSnWNb nanoalloys as efficient and stable catalysts for ethanol oxidation electrocatalysis.

Ternary nanoalloys used as electrochemical ethanol oxidation catalysts for direct ethanol fuel cells are confronted with poor stability issues under harsh acidic operating conditions. To address this issue, a carbon-supported quinary PtCuSnWNb high-entropy nanoalloy (denoted as PtCuSnWNb/C) was synthesized by using a polyol reduction method. Due to the unique high-entropy mixing states and strong catalyst-support interactions, PtCuSnWNb/C shows robust structural and compositional stability.

Amorphous cobalt–nickel borides boost electrocatalytic ethanol oxidation coupled with energy-saving hydrogen production

We report an amorphous heterogeneous catalyst composed of boride and tungstate, which realizes the upgrading of ethanol oxidation coupled with energy saving hydrogen production.

A comparative study of α-Ni(OH)2 and Ni nanoparticle supported ZIF-8@reduced graphene oxide-derived nitrogen doped carbon for electrocatalytic ethanol oxidation.

Ethanol electrooxidation is an important reaction for fuel cells, however, the major obstacle to ethanol electrocatalysis is the splitting of the carbon-carbon bond to CO2 at lower overpotentials. Herein, a ZIF-8@graphene oxide-derived highly porous nitrogen-doped carbonaceous platform containing zinc oxide was attained for supporting a non-precious Ni-based catalyst. The support was doped with the disordered α-phase Ni(OH)2 NPs and Ni NPs that are converted to Ni(OH)2 through potential cycling in alkaline media. The Ni-based catalysts exhibit high electroactivity owing to the formation of the NiOOH species which has more unpaired d electrons that can bond with the adsorbed species. From CV curves, the EOR onset potential of the α-Ni(OH)2/ZNC@rGO electrode is strongly shifted to negative potential (Eonset = 0.34 V) with a high current density of 8.3 mA cm-2 relative to Ni/ZNC@rGO. The high catalytic activity is related to the large interlayer spacing of α-Ni(OH)2 which facilitates the ion-solvent intercalation. Besides, the porous structure of the NC and the high conductivity of rGO facilitate the kinetic transport of the reactants and electrons. Finally, the catalyst displays a high stability of 92% after 900 cycles relative to the Ni/ZNC@rGO and commercial Pt/C catalysts. Hence, the fabricated α-Ni(OH)2/ZNC@rGO catalyst could be regarded as a potential catalyst for direct EOR in fuel cells.