Catalysis and Reaction Engineering Commons^™

In Situ Electrochemical Characterization Techniques For Active Hydrogen In Electrocatalytic Nitrate Reduction To Ammonia, Hong-Mei Li, Mei Yi, Zhao-Yu Jin, Ming-Hao Xie, Khalid M. Omer, Yong Guo, Pan-Pan Li

Journal of Electrochemistry

Electrocatalytic nitrate reduction to ammonia (NitRR) represents a sustainable pathway that integrates environmental remediation with the production of high-value ammonia. However, the activity and selectivity of this process are limited by the generation, consumption, and dynamic equilibrium of the key transient intermediate—active hydrogen (*H). Precise modulation of *H necessitates a comprehensive understanding of its behavior, which relies fundamentally on advanced in situ electrochemical characterization techniques. However, a systematic review dedicated to the rational selection and application of in situ electrochemical techniques for the specific characterization of *H in NitRR, with clear definitions of each technique's "detectable targets, quantitative accuracy, and …

Neural Network Driven By Electrochemical Performance Data For Predicting The Discharge Termination Time Of Seawater Electrolyte-Based Metal-Air Batteries, Peng-Peng Shen, Yi-Chi Pan, Yu-Rong Liu, Lu-Dan Zhang, Ning Niu, Guan-Jun Wang, De-Kun Yang, Xin-Long Tian, Peng Rao

Journal of Electrochemistry

Seawater electrolyte-based metal-air batteries exhibit great promise for marine energy supply systems. However, conventional statistical analysis methods, though applicable to seawater metal-air battery lifetime prediction, have inherent limitations of insufficient prediction accuracy and large error. Herein, a deep time-series regression framework based on InceptionTime and incorporating prior-biased attention pooling is proposed to construct a nonlinear mapping between electrochemical performance sequences and the discharge termination time of catalysts. Specifically, chronoamperometric profiles are employed to extract long-term stability features, while prior knowledge derived from linear sweep voltammetry is introduced to strengthen the attention weighting over critical potential regions. Under a nested leave-one-catalyst-out …

Microwave-Assisted Synthesis Of Core-Shell Structured Pd@Pdptcufe Recessed Truncated Octahedral Nanocrystals For Multifunctional Electrocatalysis, De-Zhong Hu, Wen-Dan Jiang, Wei Keat Ng, Jun Yang, Xiong-Wu Kang

Journal of Electrochemistry

Developing cost-efficient and durable multifunctional electrocatalysts of hydrogen evolution reaction, oxygen reduction reaction and oxygen evolution reaction is crucial for improving energy conversion efficiency in electrolytic water splitting electrolyzer and advancing rechargeable zinc-air batteries. Polyhedral shaped nanocrystals with well-defined crystal facets represent a type of model catalysts that enables the exploration of structure-activity relationships. However, it is still very challenging to prepare alloy nanocrystals with multiple metal components due to their complicated redox potentials and mixing enthalpy. Herein, we report a rapid microwave-assisted polyol reduction method for syntheses of core-shell Pd@PdPtCu, Pd@PdPtCuNi, Pd@PdPtCuCo and Pd@PdPtCuZn octahedral nanocrystals, and recessed truncated-octahedral …

Dynamic Reconstruction Engineering Of Anti-Corrosion Ni-Based Anodes For Alkaline Seawater Electrolysis, Yi-Gang Zhang, Wen-Wen Xu, Tian-Yu Zhang, Zhi-Yi Lu

Journal of Electrochemistry

Green hydrogen production via alkaline seawater electrolysis offers an environmentally sustainable and potentially cost-effective route to address both energy and climate challenges. Achieving long-term anode stability under complex ionic environments and industrial current densities remains a central bottleneck. Specifically, Ni-based anodes exhibit intense surface reconstruction during the oxygen evolution reaction, necessitating dynamic anti-corrosion strategies. This mini review systematically summarizes reconstruction engineering approaches to develop anti-corrosion Ni-based anodes of alkaline seawater electrolysis across increasingly complex ionic environments from simulated seawater to real seawater: (i) Cl^– dominated; (ii) Cl^– with co-existing oxyanions, and (iii) Cl^–  with co-existing Br^{– …}

Preparation And Performance Study Of In-Situ Self-Assembled Biphasic Smmn2O5-Nimn2O4 Composite Cathode, Neng-Chu Xia, Yu Zhou, Qin Wang, Jia-You Zhang, Chun Yu, Yang Zhang, Wan-Bing Guan, Jian-Xin Wang

Journal of Electrochemistry

Mullite-structured oxides exhibit excellent oxygen reduction reaction activity, possess a low thermal expansion coefficient due to their unique crystal structure, and can eliminate the need for a barrier layer and simplify the preparation process as they contain no alkaline earth elements. Thus, they hold great promise as novel cathode materials for solid oxide fuel cells. In this work, a mullite-spinel-structured SmMn₂O₅-NiMn₂O₄ (SMO-NMO) composite cathode was one-step synthesized via a solid-liquid composite route, and its in-situ self-assembly enabled good compatibility with the electrolyte without any barrier layer. Characterization results showed that the SMO:NMO = …

In-Situ Stm Visualization Of Molecular Structural Evolution During Electrochemical Oxidation Coupling Of Para-Aminothiophenol On Au(111), Zi-Wei Ma, Tai-Rui Wu, An-Ni Zheng, Lai-Ke Chen, Yuan-Hui Xiao, Zhao-Bin Chen, Qing-Na Zheng, Jian-Zhang Zhou, Jia-Wei Yan, De-Yin Wu

Journal of Electrochemistry

Para-aminothiophenol (PATP) is not only a widely-used probe molecule in the field of surface-enhanced Raman spectroscopy (SERS), but also an important model molecule for interfacial reactions, exhibiting distinct photo- and electro-oxidation pathways, so that PATP is selectively activated under different external fields. The evolution of products and intermediates during electrochemical oxidative coupling remains unknown. In this study, we have investigated the dynamic electrochemical oxidation process of PATP on the Au(111) surface using cyclic voltammetry, electrochemical (EC)-SERS, and in situ electrochemical scanning tunneling microscopy (EC-STM). The results showed that PATP forms an unsaturated adsorption coverage on Au(111) in an acidic solution. …

Effect Of Concentration And Temperature Of Tio2-Al2o3 Hybrid Nanofluid On The Corrosion Rate Of Aluminum Radiator, Ratna Monasari, Rizky Maulana Ramadhan, Nike Nur Farida, Ahmad Hanif Firdaus, Supa Kusuma Aji, Yuniarto Agus Winoko, Rizkyansyah Alif Hidayatullah

Journal of Mechanical Engineering Science and Technology (JMEST)

Corrosion of aluminum radiators can reduce cooling system reliability and shorten service life in automotive applications. This study examines the effect of TiO₂-Al₂O₃ hybrid nanofluid concentration and temperature on the corrosion rate of commercially available aluminum radiator material. Hybrid nanoparticles with a TiO₂-Al₂O₃ mass ratio of 50:50 were dispersed in distilled water at concentrations of 0.6 wt.%, 0.8 wt.%, and 1.0 wt.%. Corrosion behavior was evaluated using a 14-day accelerated immersion test at 60°C and 80°C, and the corrosion rate was determined using the gravimetric mass loss method. The results …

Li+/Na+ Hybrid Ion Conduction Mechanism In The Superionic Conductor Li3–XNaXZr2Si2Po12, Yi-Hong Wu, Xia Xie, Lei Zhu, Mu-Ran Yu, Guo-Tai Zhang, Jun-Chao Chen, Shu-Ying Sun, You-Wei Wang, Wei-Ping Tang

Journal of Electrochemistry

Hybrid ion conductors that transport multiple ionic conductive species provide a useful platform for understanding how mixed-ion transport governs ionic conductivity within a single phase. However, the controlled introduction of multiple mobile ions into solid-state electrolytes and a mechanistic understanding of their migration within the framework remain challenging. Herein, a skeleton-retained Li⁺↔Na⁺ cationic exchange was used to simultaneously induce Li⁺ and Na⁺ cations into the NASICON-type framework of Li_3–xNa_xZr₂Si₂PO₁₂ (0 < x < 3). We show that the interpenetration of NaO₆ and NaO₈ coordination polyhedra significantly influences the ionic conductivity of hybrid ion conductors. Computational …

Distribution And Transport Of Lithium Ions At Interfaces Between Graphite And Carboxymethyl Celluloses, Zi-Jun Huang, Zhen-Ying Zheng, Hua-Wei Cao, Jian Wang, Qing-Feng Zhang, Sheng-Li Chen

Journal of Electrochemistry

Carboxymethyl cellulose (CMC) is a water-processable binder widely used for graphite anodes. However, a microscopic understanding of why the identity of CMC counterions (Li⁺/Na⁺/K⁺) strongly affects electrode performance remains limited. Here, molecular dynamics (MD) simulations are used to track Li⁺ transport accessibility across electrolyte/CMC/graphite three-phase interfaces, comparing pure CMC-Li, CMC-Na, CMC-K, and mixed-counterion CMC binders. We find that CMC-Li sustains a continuous Li⁺ transport pathway from the electrolyte through the binder phase toward graphite. In contrast, in CMC-Na and CMC-K, Na⁺/K⁺ ions preferentially enrich at the graphite/binder interface, forming …

Distinct Co2 Electroreduction Behaviors Over Planar And Non-Planar Cobalt Molecular Catalysts, Ru Jia, Cheng-Biao Zhu, Zi-Mo Zhang, Tuo Wang, Kai-Cong Yang, Guang-Zhe Wang, Yang Hu, Ting-Ting Zhang, Zhen-Wei Wei, Li Xiao, Gong-Wei Wang, Lin Zhuang

Journal of Electrochemistry

Molecular catalysts serve as ideal platforms for studying electrocatalytic reaction mechanisms. While current research mainly focuses on modulating central metals or surrounding ligands, the influence of molecular spatial configuration remains largely unexplored. Herein, we synthesized two cobalt complexes with similar ligand environments but distinct spatial geometries, a planar cobalt hexaazamacrocyclic complex (CoHAM) and a non-planar acyclic Co(phen)₂Cl₂, and evaluated their performance in CO₂ reduction reaction (CO₂RR). The planar CoHAM exhibited dramatically superior CO₂RR performance compared to the non-planar Co(phen)₂Cl₂. Through a series of combined analyses using in-situ …

Physicochemical Properties And Chemical Compositions Of Cashew Nut Shell Liquid Extracted With Carbon Dioxide–Expanded Hexane, Neema Msuya, Joseph Yn Philip, Frank Jacob, Kando K. Janga

Tanzania Journal of Engineering and Technology (TJET)

Cashew nut shell liquid (CNSL) is a mixture of phenolic compounds that can effectively replace commercially available phenols in various applications. This study investigated the physicochemical properties and chemical composition of CNSL extracted using CO₂–expanded hexane (CXH) and compared to the traditional Soxhlet extraction method. Steamed cashew nut shells (sCNS) were used in both cases.  The CXH was carried under varying CO₂-mole fractions (0.468-0.892) and temperatures (20-36 °C) whereas Soxhlet extraction was performed at atmospheric pressure and hexane boiling point. Response Surface Methodology (RSM) with Central Composite Face-Centred Design (CCFD) was employed to evaluate the effect …

Photocatalysts Based On Titanium Dioxide And Zinc Phthalocyanine Composites For Photodegradation Of Methylene Blue, Albert R. Koldarov, Mastura Kh. Aripova, Odilzhon E. Abdurakhmonov, Zuhra Ch. Kadirova, Abror O. Tashpulatov

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is to analyze the photocatalytic degradation of a model methylene blue solution using titanium dioxide composites with zinc phthalocyanine as the sensitizing photocatalyst under sunlight. The objects of the study are TiO₂-based photocatalysts derived from the spent catalyst of the Shurtan GCC after heat treatment at 650°C (T-650), as well as a composite containing zinc phthalocyanine (T-650/PcZn). It has been established that the photodegradation reaction follows a pseudo-first-order model, while the rate constant for the TiO₂/PcZn composite is significantly higher than that of pure TiO₂, indicating greater efficiency. The …

Modulating Electronic Structure With Linearly Fused Pyrazine Units For High-Voltage And Stable Zinc-Organic Batteries Cathode, Min-Jian Zhao, Li-Bin Zhang, Jin-Tao Wang, Kun Ding, Hai-Mei Liu, Yong-Gang Wang

Journal of Electrochemistry

High-voltage n-type organic cathode materials are critical for constructing zinc-organic batteries (ZOBs) with high energy density and long cycle life. However, the intrinsically unfavorable electronic structures and relatively high LUMO energy levels of most n-type materials often lead to sluggish kinetics, high solubility, and suboptimal discharge voltages (< 0.8 V). Here, we design a small molecule, quinoxalino[2’,3’:5,6]pyrazino[2,3-f][1,10]phenanthroline (DPQP), as a ZOB cathode by introducing locally electron-deficient motifs into the conjugated backbone of aromatic compounds. The linearly fused pyrazine units extending the pyrazine–benzene framework effectively optimize the electronic structure, thereby significantly enhancing the discharge voltage. Meanwhile, the expanded π-conjugated plane suppresses dissolution and accelerates charge-transfer kinetics. Benefiting from these features, the DPQP electrode exhibits an exceptional increase in average operating voltage from 0.61 V to 1.07 V (vs. Zn²⁺/Zn) at 0.1 A·g^–1, with an overpotential of only 140 mV. Notably, no discernible voltage decay occurs as the current density increases, indicating rapid and highly reversible redox kinetics. Furthermore, the DPQP cathode delivers outstanding cycling stability, maintaining over 2000 h of continuous operation at 0.1 A·g^{–1 …}

(Co,Ni,Mn,Cu,Zn)O High-Entropy Oxide Nanotubes As Efficient Bifunctional Electrocatalyst For Oxygen Evolution And Hydrazine Oxidation Reactions, Pan-Yan Chen, Wan-Wan Wu, Heng Bian, Wei-Wei Li, Xin-Sheng Zhao, Lu Wei

Journal of Electrochemistry

High-entropy oxides (HEOs) present significant scientific challenges in both design and synthesis due to their multielement and high-entropy nature, which involves complex combinations of multiple metal cations and oxygen anions, typically arranged in equimolar ratios to achieve structural stability. Herein, one-dimensional (Co,Ni,Mn,Cu,Zn)O high-entropy oxide nanotubes (HEO-NTs) are fabricated by means of a gradient electrospinning strategy with a tailored polyvinyl alcohol (PVA) molecular weight distribution and controlled pyrolysis. Benefiting from the HEO features and the synergistic effect of multicomponent sites, the as-synthesized (Co,Ni,Mn,Cu,Zn)O HEO-NTs exhibit exceptional bifunctional electrocatalytic activity for the oxygen evolution and hydrazine oxidation reactions (OER/HzOR). This study offers …

Zirconium Metal-Organic Cages: Synthetic Development Of Chromium-Functionalized Ligands, Jim P. Heller, Jonathan E. Pines, Miguel I. Gonzalez

Wetterhahn Science Symposium Posters

Metal-organic cages (MOCs) are a class of highly porous molecules composed of inorganic clusters bridged by highly tunable organic ligands. The synthesis and development of various ligands could allow for more selective and efficient catalysts. Specifically, Chromium-based homogeneous catalysts have recently been commercialized due to their high selectivity in the production of 1-hexene and 1-octene. This project aims to synthesize reusable heterogeneous catalysts composed of chromium-functionalized zirconium MOCs deposited on mesoporous supports.

The current focus of this project is to synthesize and purify the "SNS Ligand." This ligand can coordinate to chromium via its S—N—S moiety. This project specifically focuses …

Techno-Economic Assessment And Life Cycle Analysis Of Electrocatalytic Reduction Of Co2 To Ethanol., Omotolani Elizabeth Oduyebo

LSU Master's Theses

This study presents a techno-economic analysis (TEA) and life cycle assessment (LCA) of the electrocatalytic reduction of CO₂ to ethanol, a multi-carbon (C₂) product with significant market value. Prior TEA studies have relied on simplified lump-sum separation cost estimates, and prior LCA studies have rarely examined the combined effect of CO₂ source and electricity supply on carbon intensity gaps that this work addresses through process-simulation-grounded analysis. An Aspen Plus process simulation was developed for an anion-exchange membrane (AEM) electrolyzer system coupled with an extractive distillation separation train using ethylene glycol as the entrainer, achieving 99.9 wt.% ethanol purity …

Synthesis And Investigation Of Tungsten–Copper Oxide Composites For Enhanced Photocatalytic Applications, Janak Paudel, John Nichols

Research and Creative Works Expo

No abstract provided.

Impact Of Biomass Type On Hydrocarbon Yield And Chain Length Distribution Produced Via Fischer-Tropsch Synthesis, Nicholas R. Hawe

Honors Scholar Theses

This paper investigates the relationship between biomass composition and hydrocarbon yield as well as chain length distribution produced by Fischer-Tropsch synthesis. Through an Aspen Plus model, the conversion of three different biomasses – digestate, sawdust, and corn stover – into hydrocarbon fuel was simulated. The model converts biomass into gaseous and liquid hydrocarbons via various unit operations and reactions. Simulation results highlight the product distribution and hydrocarbon output, allowing for an analysis of hydrocarbon yield and comparison of chain length distributions amongst the three biomasses. Overall, the simulation showed biomass composition had no significant impact on hydrocarbon yield or chain …

Development Of A Metal-Based Catalyst For The Ammonia Dehydrogenation Reaction, Othman Mohammed Abdullah Al-Amodi

Thesis/ Dissertation Defenses

Developing cost-effective and active catalysts that would replace noble metals is desirable for the ammonia decomposition reaction. Hence, this thesis focuses on the development and evaluation of a 10Ni/0.75TiO2-0.25CeO2 catalyst for ammonia decomposition, a promising route to carbon-free hydrogen production. The system parameters investigated include the effect of reaction temperature (550, 650, and 750°C) and the catalyst mass (100, 200, and 300 mg) on the performance of the ammonia decomposition process. The primary objective of this work is to investigate how catalyst composition and metal-support interactions influence activity, hydrogen production, and ammonia conversion. Catalysts were prepared by the incipient wetness …

Optimization Of Renewable Energy-Based Alkaline Electrolysis Systems For Sustainable Hydrogen Production, Shokhrukhbek Kozimjon Ugli Bakhramov

Chemical Technology, Control and Management

This paper presents a comprehensive optimization study of hydrogen production systems through alkaline water electrolysis powered by photovoltaic energy sources, with a specific focus on Central Asian applications. The research systematically investigates critical operating parameters including KOH electrolyte concentration (25-30 wt%), temperature effects (25-80°C), current density optimization (100-500 mA/cm²), and electrode material performance using cost-effective 316L stainless steel. Experimental results demonstrate that optimized systems achieve solar-to-hydrogen efficiency of 13-15%, with hydrogen production costs ranging from $2-8/kg depending on system scale. The study reveals that maximum performance occurs at 30 wt% KOH concentration, 60-80°C operating temperature, and 200-400 mA/cm² current density. …