Active Catalyst Research Articles

Modulating electronic structure of Fe site by adjacent Cu site through orbital coupling in Cu-Fe2O3 catalyst derived from Fenton sludge quenching

The incorporation of specific atoms into catalysts derived from Fenton sludge has the potential to regulate active site for promoting peroxymonosulfate (PMS) activation. Here, quenching technology was employed in this study to facilitate the production of a highly active Fe2O3-based catalyst from Fenton sludge. In this process, Cu atoms effectively substituted Fe atoms and regulated the local electronic structure of neighbouring Fe sites, thereby enhancing the catalytic performance in PMS activation for the degradation of Levofloxacin (LEVO) in wastewater. The strong orbital coupling between Fe and Cu, as confirmed by comprehensive characterization and density functional theory (DFT), facilitated the delocalization of d-orbital electrons, thereby enabling efficient electron transfer and redox cycling of Cu2+/Cu+ and Fe3+/Fe2+. This allowed degradation reaction to proceed continuously. The present study will offer a novel approach to the design of Fenton sludge derived catalysts, thereby expanding the utilization of quenching chemistry in solid waste recycling.

Coordination-based synthesis of Fe single-atom anchored nitrogen-doped carbon nanofibrous membrane for CO2 electroreduction with nearly 100% CO selectivity

Carbon-based materials with single-atom (SA) transition metals coordinated with nitrogen (M-Nx) have attracted extensive attention due to their superior electrochemical CO2 reduction reaction (CO2RR) performance. However, the uncontrolled recombination of metal atoms during the typical high-temperature synthesis process in M-Nx causes deterioration of CO2RR activity. Herein, by using electrospinning, we propose a novel strategy for constructing a highly active and selective SA Fe-modified N-doped porous carbon fiber membrane catalyst (Fe-N-CF). This carbon membrane has an interconnected three-dimensional structure and a hierarchical porous structure, which can not only confine Fe to be single atom as active centers, but also provide a diffusion channel for CO2 molecules. Relying on its special structure and stable mechanical properties, Fe-N-CF is directly used for CO2RR, which presents an excellent selectivity (CO Faradaic efficiency of 97%) and stability. DFT calculations reveals that the synthesized Fe-N4-C can significantly reduce the energy barrier for intermediate COOH* formation and CO desorption. This work highlights the specific advantages of using electrospinning method to prepare the optimal SA catalysts.

3D hollow superstructures endow PdAg electrocatalyst with selective ethanol electrooxidation

Direct ethanol fuel cells (DEFCs) have been considered as future power devices for many portable applications. The ethanol oxidation reaction (EOR), that is, a multielectron process, suffers from low efficiency owing to the high selectivity to the 4e− pathway (C2 pathway) and low selectivity to the 12e− pathway (C1 pathway). The preparation of efficient catalysts with high C1 pathway selectivity is regarded as a promising and fascinating field. Herein, we first advance a one-pot synthesis of 3D PdAg superstructures (SSs) with a hollow interior and ultrathin nanosheet shell. PdAg SSs achieve a mass activity of 5.27 A mg−1 for the alkaline EOR and a Faraday efficiency of 22.7 % for the C1 pathway, which is 5.7 and 7.5 times higher than that of commercial Pd/C, respectively. Mechanism studies confirm that the construction of the Pd-Ag system greatly facilitates the oxidation of the C1 intermediates (*CH3 and *CO) and enhances the CC bond cleavage ability of the catalyst. This work not only highlights an active Pd-based catalyst for the selective EOR, but also sheds light on the formation of 3D open nanostructure via self-assembly of 2D nanosheets.

Catalytic synergy: N,P modification of activated carbon for improved 1-chloro-4-nitrobenzene reduction

Carbon materials have emerged as a new generation of catalysts for the crucial industrial hydrogenation of nitroarenes. Activated carbon, known for its cost-effectiveness and facile modifiability, stands out among various carbon materials. This study focuses on the preparation of N and P co-doped carbons for catalysing the hydrogenation of 1-chloro-4-nitrobenzene. Comprehensive characterisation using thermal analysis (TGA-MS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, N2 adsorption at −196 °C, and ICP-MS was performed. The synergistic effect of N and P was evident, with co-doped carbons outperforming their mono-doped counterparts, underscoring the significance of nitrogen. N,P-codoped activated carbon emerges as a promising, active, stable, and selective metal-free catalyst for the hydrogenation of 1-chloro-4-nitrobenzene, leading to 4-chloroaniline.

Pt-N catalytic centres concisely enhance interfacial charge transfer in amines functionalized Pt@MOFs for selective conversion of CO2 to CH4

Improving ligand-to-active metal charge transfer (LAMCT) by finely tuning the organic ligand is a decisive strategy to enhance charge transfer in metal organic frameworks (MOFs)-based catalysts. However, in most MOFs loaded with active metal catalysts, electron transmission encounters massive obstacle at the interface between the two constituents owing to poor LAMCT. Herein, amines (–NH2) functionalized MOFs (NH2-MIL-101(Cr)) encapsulated active metal Pt nanoclusters (NCs) catalysts are synthesized by the polyol reduction method and utilized for the photoreduction of CO2. Surprisingly, the introduction of –NH2 (electron donating) groups within the matrix of MIL-101(Cr) improved the electron migration through the LAMCT process, fostering a synergistic interaction with Pt. The combined experimental analysis exposed the high number of metallic Pt (Pt0) in Pt@NH2-MIL-101(Cr) catalyst through seamless electron shuttling from N of –NH2 group to excited Pt generating versatile hybrid Pt-N catalytic centres. Consequently, these versatile hybrid catalytic centres act as electro-nucleophilic centres, which enable the efficient and selective conversion of CO bond in CO2 to harvest CH4 (131.0 µmol.g−1) and maintain excellent stability and selectivity for consecutive five rounds, superior to Pt@MIL-101(Cr) and most reported catalysts. Our study verified that the precise tuning of organic ligands in MOFs immensely improves the surface-active centres, electron migration, and catalytic selectivity of the excited Pt NCs catalysts encaged inside MOFs through an improved LAMCT pathway.

Crystalline-dependent surface reconstruction at low applied potential region for enhanced oxygen evolution reaction

Alkaline water electrolysis is apreferred technology for large-scale green hydrogen production. For most active transition metal-based catalysts during anodic oxygen evolution reaction (OER), the atomic structure of the anodic catalysts’ surface often undergoes reconstruction to optimize the reaction path and enhance their catalytic activity. The design and maintenance of highly active sites during this reconstruction process remain critical and challenging for most OER catalysts. In this study, we explored the effects of crystal structures in pre-catalysts on surface reconstruction at low applied potential. Through experimental observation and theoretical calculation, we found out that catalysts with specific crystal structures exhibit superior surface remodeling ability, which enables them to better adapt to the conditions of the oxygen evolution reaction and achieve efficient catalysis. The discharge process enables the formation of abundant phosphorus vacancies on the surface, which in turn affects the efficiency of the entire oxygen evolution reaction. The optimized crystal structure of the catalyst results in an increase as high as 58.5 mA/cm2 for Ni5P4, which is twice as high as that observed for Ni2P. These results provide essential theoretical foundations and technical guidance for designing more efficient catalysts for oxygen evolution reactions.

An investigation of photocatalytic and biological properties of Croton bonplandianum-mediated Ag-Cu bimetallic nanoparticles

The green synthesis of nanoparticles using plant parts and their essence is considered an archetypal tactic in material synthesis for environmental beneficence. Multitudinous metal nanoparticles with potential bioactivities have been prepared based on plant extract. This study's main objective is synthesizing Ag-Cu bimetallic nanoparticles (Ag-Cu BMNPs) using leaf extract of Croton bonplandianum L (CB). Furthermore, its photocatalytic, antibacterial, anti-fungal, and anti-tuberculosis activities are systematically investigated in detail. The surface morphology of the prepared sample is shown to be highly porous, with an average grain size of ∼ 16 nm. The FTIR spectra exhibited that the phytomolecules from CB leaf extract serve as a capping and reductantfor forming Ag-Cu BMNP. Brunauer-Emmitte-Teller (BET) comprehends the CB leaf extract to be an active, cost-effective, reusable, and high surface area catalyst. The sample exhibited improved photocatalytic activity with an efficiency of 92.31 % at the moderate catalyst dose of 30 mg against methylene blue (MB) dye. Ag-Cu BMNPs exhibited a 17 mm inhibition zone at higher concentrations against both gram (+ve) and gram (−ve) bacterial strains. Also, the synthesized Ag-Cu BMNPs produced a clear inhibition zone of 16 mm and 15 mm at lower concentrations. The anti-fungal activity against A. flavus and C. albicans at higher and lower concentrations produced a clear inhibition zone of 17 mm,15 mm, and 6 mm, 9 mm, respectively. In addition, the anti-tuberculosis activity against Mycobacteria tuberculosis exhibited good results at a 0.4 µg/mL concentration for the synthesized sample. Moreover, Ag-Cu BMNPs enhanced their biological ability and did not increase their cytotoxicity, which provides a potential for the clinical applications of Ag-Cu BMNPs. In general, the suggested method for producing Ag-Cu bimetallic nanoparticles is successful in combating microbiological diseases.

Constructing quasi‐amorphous cobalt oxyhydroxide nanowires with synergy of anion and cation via ion exchange reconstruction for large-current–density oxygen generation

Deep insight into the synergy between anion and cation aids in the maximization of catalytic activity and the rational exploitation of efficient oxygen-evolving catalysts. However, how to use ion exchange reconstruction to devise highly active and cost-efficient oxygen evolution reaction (OER) catalysts with anion and cation synergies for water electrolysis is rarely reported. Herein, the cobalt triphosphide (CoP3) nanowires are elaborately devised as a component-flexible precatalyst for directing an anodic reconfiguration with Ni cation exchange to construct a highly active and quasi‐amorphous cobalt oxyhydroxide (CoOOH) catalyst integrated with cation (Ni) substitution and oxyanion (PO43-) decoration (denoted by R-(Ni)CoP3). Interestingly, the structural evolution and the Ni cation exchange processes are captured through various in/ex situ techniques. The resultant R-(Ni)CoP3 nanowires display a splendid activity with low overpotentials of 406 and 420 mV to respectively deliver industrial grade current densities of 1000 and 1500 mA cm−2, and an outstanding stability over 300 h at a large current density of 500 mA cm−2, superior to most progressive cobalt-based OER materials and the benchmark IrO2. The combination of theoretical calculations with experimental studies demonstrate that the synergy of cation (Ni) substitution and oxyanion (PO43-) decoration can significantly modulate the electronic states of CoOOH and optimize the adsorption free energy of OER intermediates, thus immensely expediting the kinetics process and enhancing the charge transfer ability and the intrinsic OER activity. This research suggests ion-regulatory reconfiguration as a flexible and changeable strategy to construct various efficient and advanced catalysts for water electrolysis and beyond.

Pomelo peel biomass derived highly active advanced-oxidation-process catalyst: Complete elimination of organic pollutants

The advanced oxidation process (AOPs) is playing an important role in the elimination of hazardous organic pollutants, but the development of inexpensive and highly active advanced catalysts is facing challenges. In this study, a low-cost and readily available agricultural waste resource pomelo peel-flesh (PPF) biomass was used as the basic raw material, and the uniformly dispersed small cobalt nanoparticles were effectively anchored in the biochar derived from pomelo peel-flesh (BDPPF) by impregnation adsorption/complexation combined with heat treatment. Co/BDPPF (BDPPF embedded with Co) can effectively activate peroxymonosulfate (PMS) to SO4·-, ·OH and 1O2 reactive oxygen species, and achieve nearly 100% degradation of tetracycline persistent organic pollutant. Co/BDPPF can not only degrade tetracycline efficiently in complex water environment, but also degrade most organic pollutants universally, and has long-term stability, which solves the problem of poor universality and stability of heterogeneous catalysts to a certain extent. Importantly, Co/BDPPF derived from waste biomass was also innovatively designed as the core of an integrated continuous purification device to achieve continuous purification of organic wastewater. In this study, agricultural waste resources were selected as biomass raw materials to achieve efficient capture of Co2+, and finally developed advanced AOPs catalyst with excellent performance to achieve the purification of organic wastewater. It also provides a promising solution for the preparation of simple, low-cost, large-scale production of AOPs catalysts that can be put into actual production.

Catalytic styrene combustion over Pt/ZSM-5 Catalysts: Elucidating the deactivation mechanism induced by surface acid sites

Catalytic oxidation plays a pivotal role in styrene elimination, yet the development of highly active and robust catalysts remains a challenge. This work aims to elucidate the mechanisms underlying styrene oxidation and catalyst deactivation over the Pt@ZSM-5 catalyst. The Pt@ZSM-5 catalyst with low Si/Al ratio and high surface acidity leads to generation of small Pt particle, the initial activity of the catalyst varies in a volcanic curve with the size of Pt particles. Notably, the Pt@ZSM-5–40 catalyst with Pt particle size of 3.3 nm exhibits the highest reaction rate of 1.6 µmol gPt−1 s−1 at 100 °C. However, the Pt@ZSM-5 catalysts undergo significant deactivation at their T80 (the temperature styrene conversion of 80 %). Through comprehensive characterizations and detailed mechanistic studies, it has been observed that intermediates from styrene oxidation accumulate heavily on the catalyst, especially for the Pt@ZSM-5 catalyst with high acidity. Improving the reaction temperature could inhibit the deactivation which is dependent on the surface acidity of Pt@ZSM-5 catalyst. For instance, the Pt@ZSM-5–800 and Pt@ZSM-5–1200 catalysts remains high activity when reaction is operated at T99+30, whereas a substantially higher reaction temperature (T99+80) is required for both Pt@ZSM-5–18 and Pt@ZSM-5–40 catalysts to counteract deactivation. Our primary results provide insights to develop effective and robust catalyst for styrene oxidation.

Synthesis and testing of active and water resilient low temperature methane combustion catalysts

Synthesis and testing of active and water resilient low temperature methane combustion catalysts

Wonton-structured KB@Co-C3N4 as a highly active and stable oxygen catalyst in neutral electrolyte for Zinc-air battery

This work addresses the challenges faced by oxygen catalysis applications in neutral media, which are hindered by sluggish kinetics and severe carbon corrosion. To overcome these issues, a bifunctional oxygen catalyst (KB@Co-C3N4) was developed by utilizing graphitic carbon nitride (g-C3N4) to support Co-Nx active sites and simultaneously to wrap Ketjen black (KB) to form a wonton structure. The resulting catalyst exhibited excellent ORR/OER activity and good stability in neutral electrolytes. The KB@Co-C3N4 catalyst demonstrated a half-wave potential (E1/2) of 0.723 V and only a 9 mV decay after 40000 cycles of ORR accelerated durability test (ADT). In terms of OER, the overpotential at 10 mA cm−2 (η10) of KB@Co-C3N4 was 550 mV, with negligible increase observed even after 20 k cycles of OER ADT. The zinc-air battery incorporating KB@Co-C3N4 exhibited superior performances over other benchmark bifunctional counterparts in open-circuit voltage (1.52 V), galvanostatic discharge/charge performance and cycling duration (985 h at 5 mA cm−2). The theoretical investigation revealed that the engineered electronic structures of the metal active sites enable precise regulation of the charge distribution of Co centers, leading to optimized adsorption and desorption of oxygenated intermediates. The high stability of the catalyst is attributed to the chemically stable C3N4, which strengthens Co-Nx active sites and protects KB against carbon corrosion by wrapping KB to form the wonton structure.

A Mixed-Valence Ti(II)/Ti(III) Inverted Sandwich Compound as a Regioselective Catalyst for the Uncommon 1,3,5-Alkyne Cyclotrimerization.

The synthesis, structure, and catalytic activity of a Ti(II)/Ti(III) inverted sandwich compound are presented in this study. Synthesis of the arene-bridged dititanium compound begins with the preparation of the titanium(IV) precursor [TiCl2(MesPDA)(thf)2] (MesPDA = N,N'-bis(2,4,6-trimethylphenyl)-o-phenylenediamide) (2). The reduction of 2 with sodium metal results in species [{Ti(MesPDA)(thf)}2(μ-Cl)3{Na}] (3) in oxidation state III. To achieve the lower oxidation state II, 2 undergoes reduction through alkylation with lithium cyclopentyl. This alkylation approach triggers a cascade of reactions, including β-hydride abstraction/elimination, hydrogen evolution, and chemical reduction, to generate the Ti(II)/Ti(III) compound [Li(thf)4][(TiMesPDA)2(μ-η6: η6-C6H6)] (4). X-ray and EPR characterization confirms the mixed-valence states of the titanium species. Compound 4 catalyzes a mild, efficient, and regiospecific cyclotrimerization of alkynes to form 1,3,5-substituted arenes. Kinetic data support a mechanism involving a binuclear titanium arene compound, similar to compound 4, as the resting state. The active catalyst promotes the oxidative coupling of two alkynes in the rate-limiting step, followed by a rapid [4 + 2] cycloaddition to form the arene product. Computational analysis of the resting state for the cycloaddition of trimethylsilylacetylene indicates a thermodynamic preference for stabilizing the 1,3,5-arene within the space between the two [TiMesPDA] fragments, consistent with the observed regioselectivity.

Supported Ni nanoparticles derived from MOFs as a highly active catalyst for benzene hydrogenation

Metal-organic frameworks (MOFs) is easy to agglomerate at high temperature, resulting in the rapid collapse of the MOFs structure and the aggregation of metal sites. In this paper, Al2O3 is used as the support material to support the in-situ synthesis of Ni-MOF on the surface, and the metal Ni nanoparticles are successfully fixed on the Al2O3. The results showed that both Ni/Ni-MOF-300 and Ni/NA-MOF-300 catalysts reduced at 300 ℃ have good hydrogenation activity of benzene, and Ni/Ni-MOF-450 catalysts reduced at 450 ℃ formed huge Ni aggregates, which significantly reduced the hydrogenation activity of benzene. However, Ni/NA-MOF-450 catalyst reduced at 450 ℃ can effectively resist the metal Ni agglomeration caused by the collapse of MOFs structure at high temperature, and has better hydrogenation activity of benzene.

A bifunctional catalyst derived from copper metal−organic framework for highly selective photocatalytic CO2 reduction and CO2 cycloaddition reaction

Highly efficient conversion of CO2 into valuable chemicals using green chemical reactions is attractive to the alleviation of global warming. Developing active catalysts with high selectivity remains challenging and is still in pursuit. Herein, a Cu-based metal−organic framework was successfully synthesized by a facile method and denoted as CuTIA. The obtained CuTIA with rich Lewis acid/base sites exhibited enhanced CO2 affinity and served as a bifunctional catalyst for CO2 conversion. To be specific, CuTIA converted CO2 into CH4 (103.78 μmol g−1 h−1) with a selectivity of 100 % under visible light irradiation. Besides, CuTIA drove CO2 cycloaddition reaction with epoxides to produce cyclic carbonates with a yield almost 100 % under mild conditions. This study provides a new perspective in the fabrication of bifunctional catalysts for enhancing CO2 conversion.

The Oscillatory Behaviour of Cu-ZSM-5 Catalysts for N2O Decomposition: Investigation of Cu species by complementary techniques.

Copper-exchanged ZSM-5 (Cu-ZSM-5) is a promising catalyst thanks to the Cu redox pair. A particular feature of this material consists in the presence of spontaneous isothermal oscillations which take place during N2O decomposition reaction, depending on the operating conditions. In the present work, a set of five Cu-ZSM-5 catalysts are synthesised by three procedures and three different copper precursor concentrations: i) wet impregnation, ii) single ion exchange, and iii) double ion exchange. Catalytic tests reveal that the ion-exchanged samples exhibit a low catalytic activity and no oscillatory behaviour, except for the twice-exchanged sample which achieves an average N2O conversion of 26% at 400 °C. Conversely, the impregnated samples reach higher levels of N2O conversion (66% for Cu5ZSM5_WI and 72% for Cu10ZSM5_WI) and demonstrate a similar oscillating pattern. Further investigations disclosed that the most active catalysts, characterised by the presence of oscillatory behaviour, have more abundant and easily reducible copper specis (ICP, EDX and H2-TPR) which interacts better with the zeolitic support (FT-IR). Catalytic tests under a long time on stream (TOS) suggest that either self-organised patterns or deterministic chaos can be achieved during the reaction, depending on the operating conditions, such as temperature and contact time.

Bimetallic Ni-Fe Supported by Gadolinium Doped Ceria (GDC) Catalyst for CO2 Methanation

CO2 conversion into fuels and high value-added chemical feedstocks, such as methane, has gained novel interest as a crucial process for further manufacturing multi-carbon products. Methane, CH4, becomes a promising alternative for environmental and energy supply issues. Nickel-based catalysts were found to be very active and selective for CH4 production. The use of promoter and support material to develop high activity, high selectivity, and durable catalysts for CO2 methanation at low temperature is a challenge. Gadolinium-Doped Ceria (GDC) has been known as material for Solid Oxide Fuel Cell (SOFC) and Solid Oxide Electrolysis Cell (SOEC) due to higher ionic conductivity and lower operating temperatures. However, few researches have been done regarding to CO2 methanation over GDC as catalyst support so far. In this present work, CO2 methanation was investigated over bimetallic Ni-Fe catalyst supported by GDC. The results showed that CH4 production rate by using Ni-Fe/GDC catalyst was higher than that of GDC at all reaction temperatures carried on. Ni-Fe/GDC showed remarkable CH4 production rate as of 17.73 mmol.gcat−1.h−1 at 280 °C. No catalytic activity was produced by GDC catalyst only. The highest CO2 conversion (46.50%) was observed at 280 °C, with almost 100% selectivity to CH4. The turnover frequency (TOF) value of Ni-Fe/GDC (4529.32 h−1) was the highest than that of Ni and common CO2 methanation catalyst, Ni/Al2O3 catalysts at 280 °C, further displaying the outstanding low-temperature catalytic activity. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Sustainable upgrading of crude glycerol via ultrasound-reinforced bio-refinery process with oxygen–nitrogen subsistence: Co-application of reusable heterogeneous catalyst

Selective/rapid production of value-added glyceryl triacetate (GT) from catalytic transformation of crude glycerol (CG) derived from biodiesel production procedure was systematically investigated using ultrasound-reinforced bio-refinery process with environmental friendliness. Interestingly, the tartaric-magnetic mesoporous alumina (TMMA) was synthesized via hydrothermal aluminization, calcination and functionalization, further applied as an active catalyst for CG acetylation under nitrogen and/or oxygen subsistence. The operative parameters for selective synthesis of GT derived optimization process were in the sequence of TMMA loading amount > ultrasonic level > acetylation time. The GT selectivity and activation energy derived from catalytic acetylation of CG using ultrasonic system were 97.78 % and 44.38 kJ/mol while traditional system were 52.51 % and 60.66 kJ/mol. For catalytic comparison, TMMA catalyst presented better turnover rate of CG transformation than that of marketable catalysts. Moreover, TMMA catalyst could be reused for 15 cycles without notable changing in physicochemical properties such as surface area and acidity which was contributed under oxygen subsistence by oxidative degradation, leading to long-term durability of catalytic performance and long-term repression of polymeric formation. The sustainable application of O2 molecular could perfectly restrain hard polymeric deposition on TMMA structure, leading to facile separation after complete acetylation. This work anticipated that specific integration between TMMA with CG acetylation can be further co-applied for practical process of biodiesel production using ultrasound-reinforced bio-refinery process.

A general strategy for Ni0–NiOOH hybrid catalyst of high hydrogen evolution activity

Ni-based hybrid catalysts consisting of different components in variant valence state have the synergistic effect on boosting hydrogen evolution reaction (HER) activity. A general strategy is developed to achieve a Ni0–NiOOH HER hybrid catalyst, which needs to produce metal Ni0 and Ni(OH)2 concurrently. The strategy is demonstrated by two approaches, both of which include two electrochemical steps. To regular the content of the components in the hybrid catalyst, l-histidine and nitrate ions are introduced to the electrolyte in order to controlling the generation rate of Ni0 and Ni(OH)2. In terms of the two-step electrochemical technology, the pre-catalyst Ni0–Ni(OH)2 is electrochemically deposited firstly, and then electrochemical oxidized to Ni0–NiOOH, wherein Ni0 and NiOOH in different valence act as *H and *OH absorption sites, respectively. The XRD, TEM and XPS results demonstrate the coexistence of Ni0 and Ni(OH)2 in the pre-catalyst and the conversion of Ni(OH)2 to NiOOH in the final catalyst. Electrochemical tests show that the Ni0–NiOOH hybrid catalysts exhibit excellent HER activity. The overpotentials at 10 and 50 mA cm−2 are 39 mV and 88 mV, respectively, and the catalyst keeps a durable stability at 50 mA cm−2 for over 100 h. The present results suggest that the structure-performance correlations of the Ni0–NiOOH hybrid catalyst could be manipulated implementing this general deposition strategy.

MOF-derived CoP/C catalyst for efficient dibenzothiophene hydrodesulfurization

The design of an active and sulfur-resistant catalyst for dibenzothiophene (DBT) hydrodesulfurization (HDS) in crude oil purification is highly desirable but remains a grand challenge. Here, two carbon-supported cobalt phosphide catalysts Co2P/C and CoP/C, and a reference sample Co/C are successfully synthesized using a metal–organic-frameworks (MOFs) precursor. A P/Co ratio dependence on crystal phases is found, leading to the formation of two pure-phase cobalt phosphide catalysts CoP/C and Co2P/C. Catalyst evaluation in HDS of DBT shows that the CoP/C catalyst exhibits a higher activity and stability than Co2P/C and Co/C, giving a 93.7 % DBT conversion with 100 h stability under 3 MPa and 380 ◦C. Moreover, a 67.4 % biphenyl yield characterizes the dominance of the direct desulfurization (DDS) pathway. The obtained catalytic performance over the CoP/C catalyst is also superior to the published cobalt phosphide catalysts. Multiple characterization techniques co-evidence that the copious specific surface area, efficient electron transport from Co to P, high thermal stability of Co nanoparticles (NPs), and strong sulfur resistance account for the enhanced catalytic performance of CoP/C. The findings of this report suggest that phosphorus-modified cobalt over the carbon support can act as a promising catalyst for the HDS of DBT.