Catalytic Active Sites Research Articles

Construction of imide‐linked covalent organic frameworks with palladium nanoparticles for oxygen reduction reaction

AbstractCovalent organic frameworks (COFs) have been widely employed as electrocatalysts for oxygen reduction reaction (ORR) due to their diverse and tunable skeletons and pores. However, their electrocatalytic activity was limited due to the lack of highly active catalytic sites. In this work, we have first immobilized palladium nanoparticles (NPs) into the crystal, porous, and stable imide‐linked COF for ORR. The newly designed COF had pyridine linkers with imide‐linkages in the frameworks serving as the binding sites to anchor Pd sites, and the high surface area and open pore channels provide fast mass transport pathway to the active Pd sites, which contributed highly active performance in ORR. And the designed catalyst delivered onset potential and the half‐wave potential of COF‐Pd of 0.97 and 0.83 V, with a limited current density of 6.1 mA cm−2, respectively. This work provides us insights into developing high crystalline COFs with metal NPs in electrocatalytic systems.

A solution-based oxidation–reduction approach for spontaneous construction of nanowire architectures on copper metals

Copper (Cu) is a critically important functional material with widespread applications in catalysis, battery technology, and sensing. The oxidation–reduction approach serves as an efficient means to modify Cu metals, enabling the creation of nanowire architectures that expand their specific surface area and facilitate the engineering of catalytic active sites. However, the crucial issue is that the reduction process typically requires high-temperature treatment in an H2 atmosphere, which is laborious and demanding. Here using the dimethylamine methyl borane (C2H10BN) as an efficient reduction reagent, we report a facile solution-based oxidation–reduction approach at room temperature for the direct formation of the nanowire architectures on commercial Cu foams (CF), resulting in a unique three-dimensional (3D) hierarchically skeleton architecture. Moreover, as a typical application, cobalt hydroxide (Co(OH)2) is electrodeposited on the CF with nanowires (CFNW) to form a CFNW/Co(OH)2 electrode for oxygen evolution reaction (OER). The obtained results indicate the nanowire structure significantly increases the contact area between Co(OH)2 and CFNW substrate, resulting in an outstanding OER performance with an overpotential of 175 mV at 10 mA cm−2 in 1 M KOH. Importantly, this study presents a straightforward modification approach applicable to Cu metals, enabling large-scale production of advanced 3D skeleton Cu materials with diverse applications.

Positional Thiophene Isomerization: A Geometric Strategy for Precisely Regulating the Electronic State of Covalent Organic Frameworks to Boost Oxygen Reduction.

With the oxygen conversion efficiency of metal-free carbon-based fuel cells dramatically improved, the building blocks of covalent organic frameworks (COFs) raised principal concerns on the catalytic active sites with indistinct electronic states. Herein, to address this issue, we demonstrate COFs for oxygen reduction reaction (ORR) by regulating the edge-hanging thiophene units, and the molecular geometries are further modulated via positional thiophene isomerization strategy, affording isomeric COF-α with 2-substitution and COF-β with 3-substitution on the frameworks. The electronic states and intermediate adsorption ability are well-regulated through geometric modification, resulting in controllable chemical activity and local density of π-electrons. Notably, the introduction of thiophene units with different substitution positions into a pristine pure carbon-based COF model COF-Ph achieves excellent activity with a half-wave potential of 0.76 V versus the reversible hydrogen electrode, which is higher than most of those metal-free or metal-based electrocatalysts. Utilizing the combination of theoretical prediction and in situ Raman spectra, we show that the isomeric thiophene skeleton (COF-α and COF-β) can induce the dangling unit activation, accurately identifying the pentacyclic-carbon (thiophene α-position) adjacent to sulfur atom as active sites. The results suggest that the isomeric dangling groups in COFs are suitable for the ORR with promising geometry construction.

Positional Thiophene Isomerization: A Geometric Strategy for Precisely Regulating the Electronic State of Covalent Organic Frameworks to Boost Oxygen Reduction

AbstractWith the oxygen conversion efficiency of metal‐free carbon‐based fuel cells dramatically improved, the building blocks of covalent organic frameworks (COFs) raised principal concerns on the catalytic active sites with indistinct electronic states. Herein, to address this issue, we demonstrate COFs for oxygen reduction reaction (ORR) by regulating the edge‐hanging thiophene units, and the molecular geometries are further modulated via positional thiophene isomerization strategy, affording isomeric COF‐α with 2‐substitution and COF‐β with 3‐substitution on the frameworks. The electronic states and intermediate adsorption ability are well‐regulated through geometric modification, resulting in controllable chemical activity and local density of π‐electrons. Notably, the introduction of thiophene units with different substitution positions into a pristine pure carbon‐based COF model COF‐Ph achieves excellent activity with a half‐wave potential of 0.76 V versus the reversible hydrogen electrode, which is higher than most of those metal‐free or metal‐based electrocatalysts. Utilizing the combination of theoretical prediction and in situ Raman spectra, we show that the isomeric thiophene skeleton (COF‐α and COF‐β) can induce the dangling unit activation, accurately identifying the pentacyclic‐carbon (thiophene α‐position) adjacent to sulfur atom as active sites. The results suggest that the isomeric dangling groups in COFs are suitable for the ORR with promising geometry construction.

Does a Higher Density of Active Sites Indicate a Higher Reaction Rate?

A consensus view in catalysis is that a higher density of catalytically active sites indicates a higher reaction rate. Using molecular dynamics simulations capable of mimicking the electrochemical formation of gas molecules, we herein demonstrate that this view is problematic for electrocatalytic gas production. Our simulation results show that a higher density of catalytic active sites does not necessarily indicate a higher reaction rate─a high density of active sites could lead to a reduction in the rate of reaction. Further analysis reveals that this abnormal phenomenon is ascribed to aggregation of the produced gas molecules near catalytic sites. This work challenges the consensus view and lays the groundwork for better developing gas-producing reaction electrocatalysts.

Short nanotubular Fe-N-C catalysts with curved catalytic sites and contributing regions for oxygen reduction reaction

The substantial advances of non-precious Fe-N-C materials with both high activity and stability to replace platinum-based catalysts for oxygen reduction reaction (ORR) in fuel cells remain a great challenge, since their intrinsic active site design and contributing microstructure exploration are still unclear. Herein, we propose a solid-phase thermal migration strategy to synthesize Fe, N co-doped nanocarbons with a short nanotubular structure, using ferrocene as Fe source and polyaniline (PANI) as N-doped carbon nanotubes (NCNTs) source. In acidic and alkaline environments, the thermally activated Fe-N-C exhibits efficient ORR performance, and half-wave potential is 30 mV higher than a commercial Pt/C (JM, 20 wt% Pt) in alkaline medium and only 100 mV less than the Pt/C in acidic media. Impressively, the catalyst used in zinc-air battery exhibits an outstanding power density of 144.74 mW·cm−2, higher than the one assembled by the Pt/C (125.67 mW·cm−2). Combining experimental and density functional theory (DFT) calculation results, the superior ORR activity should be attributed to the formation of the efficient off-plane Fe-pyridinic-N4 species at end of the nanotubes. More important, these zigzag-type Fe-pyridinic-N4 sites at the end regions serve as the main active sites, leading to a higher ORR activity. This work opens a door to clarify the active catalytic site types and the contributing microregions of the Fe-N-C catalysts, providing ideas for designing non-noble metal catalysts with curved surfaces and rich edge structures.

Deficiency in PHD2-mediated hydroxylation of HIF2α underlies Pacak-Zhuang syndrome

Pacak-Zhuang syndrome is caused by mutations in the EPAS1 gene, which encodes for one of the three hypoxia-inducible factor alpha (HIFα) paralogs HIF2α and is associated with defined but varied phenotypic presentations including neuroendocrine tumors and polycythemia. However, the mechanisms underlying the complex genotype-phenotype correlations remain incompletely understood. Here, we devised a quantitative method for determining the dissociation constant (Kd) of the HIF2α peptides containing disease-associated mutations and the catalytic domain of prolyl-hydroxylase (PHD2) using microscale thermophoresis (MST) and showed that neuroendocrine-associated Class 1 HIF2α mutants have distinctly higher Kd than the exclusively polycythemia-associated Class 2 HIF2α mutants. Based on the co-crystal structure of PHD2/HIF2α peptide complex at 1.8 Å resolution, we showed that the Class 1 mutated residues are localized to the critical interface between HIF2α and PHD2, adjacent to the PHD2 active catalytic site, while Class 2 mutated residues are localized to the more flexible region of HIF2α that makes less contact with PHD2. Concordantly, Class 1 mutations were found to significantly increase HIF2α-mediated transcriptional activation in cellulo compared to Class 2 counterparts. These results reveal a structural mechanism in which the strength of the interaction between HIF2α and PHD2 is at the root of the general genotype-phenotype correlations observed in Pacak-Zhuang syndrome.

Melting-salt crystallization assisted controllable synthesis of core-shell zeolite catalyst for effective coupling of microwave hotspot and catalytic active site

The applications of zeolites to microwave(MW)-assisted heterogeneous reactions are limited by their MW-transparent properties, which call for essential development of core–shell catalysts with MW-absorbing cores to utilize MW hotspots efficiently. However, current preparation methods fail to address the dilemmas of high heat transfer resistance and low heat generation efficiency caused by excessively thick zeolite shells and insufficient core filling. This study proposes an innovative ship-in-bottle strategy based on melting-salt crystallization for achieving controlled preparation of core–shell zeolite catalysts with ultra-thin shells and large filling rate of MW-absorbing cores. Based on the exploration of optimal conditions, ultra-thin hollow mesoporous zeolite shells around 30 nm thickness are successfully prepared, effectively reducing the heat transfer resistance from cores to catalytic sites. Subsequently, precise adjustment of the shell mesopore size enabled quantitative filling of MW-absorbing cores and therefore successful preparation of β-MnO2@zeolite catalysts with significantly enhanced heat generation capabilities. Compared to conventional surface-loaded catalysts, the new core–shell catalysts improve toluene conversion by 44 % and paraxylene selectivity by 66 % in MW-assisted alkylation reactions. Fine numerical simulations of the catalyst heating process demonstrate that the excellent catalytic performance of core–shell catalysts is due to the effective coupling of MW hotspots and catalytic sites.

Activation of peroxymonosulfate using heterogeneous Fe-doped carbon-based catalyst to generate singlet oxygen for the degradation of sulfamethoxazole

Non-radical catalytic oxidation processes can eliminate refractory pollutants from wastewater containing complex substrates such as dissolved organic matter, but the production of selective non-radicals is challenging during the activation of peroxymonosulfate (PMS). Herein, a novel magnetic carbon-based catalyst (Fe3O4@CD-8, where 8 represents an annealing temperature of 800 ℃) with N and Fe species as catalytic active sites was fabricated to remediate sulfamethoxazole (SMX)-containing water. It showed excellent SMX removal efficiency and facilitated singlet oxygen (1O2) production. The characterization results revealed that Fe3O4@CD-8 had a microscopically hierarchical pore structure and an overall core–shell-like structure. Due to its large specific surface area, N-containing species, and Fe nanoparticles, 0.1 g/L Fe3O4@CD-8 removed almost 100% SMX (24 min) and achieved a 44.1% mineralization (40 min) efficiency in the presence of 0.5 mM PMS. This catalytic system also maintained its removal performance in the presence of inorganic anions and humic acids and over a wide pH range of 3–11, showing good tolerance to various environmental factors. 1O2 was confirmed to be the predominant active species for SMX degradation using the Fe3O4@CD-8/PMS system. Density functional theory (DFT) calculations, intermediate monitoring, and toxicity evaluation demonstrated that SMX was transformed into low-toxicity molecules and completely mineralized into CO2 and H2O. The addition of Fe nanoparticles enhanced PMS adsorption and facilitated the Fe(III)/Fe(II) redox cycle to accelerate the activation of PMS. This study provides new insights and strategies for the controlled production of non-radicals for remediating antibiotic-containing wastewater.

Significant enhanced SO2 resistance of Ce-doped OMS-2 catalyst by building the CeO2 shell for the low-temperature SCR of NO with NH3

Developing highly SO2-resistance catalysts for the NOx reduction at low temperatures is a significant challenge. In this study, we fabricate a catalyst of Ce-doped manganese oxide octahedral molecular sieve by building the CeO2 shell (Ce-OMS-2@CeO2) to solve this problem. This catalyst showed high selective catalytic reduction with NH3 (NH3-SCR) activity and enhanced resistance to SO2-induced deactivation. Ce-OMS-2@CeO2 exhibited outstanding NH3-SCR activity and anti-sulfur performance at 200 °C. The mesoporous CeO2 shells exerted no influence on the transport of reactants to catalytic active sites. The NH3-SCR on Ce-OMS-2@CeO2 catalyst occurred via the Langmuir-Hinshelwood mechanism with adsorption of NH3 and NO on different sites, thus preventing competing adsorption. The CeO2 shell bound SO2 strongly in priority, thus protecting the Ce-OMS-2 core from SO2 poisoning. Moreover, a dynamic balance was established between NH4HSO4 formation and decomposition over our Ce-OMS-2@CeO2 catalyst at low temperatures, which also hindered the SO2 poisoning in NH3-SCR reaction.

Nitrogen-doped carbonaceous electrode modified by biological metal-organic framework for vanadium redox flow batteries

The biological metal-organic framework (Bio-MOF) is utilized to modify the carbonaceous electrode for the vanadium redox flow batteries. The microwave solvothermal method prepared the cobalt-based Bio-MOF on a graphite felt (GF) surface. Then, the nitrogen-doping graphite and porous structure formation were completed simultaneously during the carbonization process. Finally, electrochemical activation was conducted to remove cobalt metal from the GF electrode and raise the concentration of oxygen-containing functional group active sites. By in-situ Raman spectroscopy, the increase of disordered graphitic lattices could be observed by raising the potential from 0.6 V to 1.6 V. The microwave solvothermal method and electrochemical activation can effectively shorten the treatment time compared with the traditional solvothermal method and acidic etching processes. Among the carbonization parameters for Bio-MOF-covered GFs, maintaining the temperature at 900 °C for 2 h under an argon atmosphere is the most suitable. The annealed sample after electrochemical activation (BMDGF-900EA) displays 73.7 % energy efficiency at 120 mA cm−2 and possesses a 90 % retention rate of efficiency after 250 cycles at 180 mA cm−2. The superior performance results from more catalytic active sites, hydrophilic surface features, and larger specific surface area prove that this modification method derived from Bio-MOF indeed provides a novel and potential way to improve the VRFB performance.

Subtle 2D/2D MXene-Based Heterostructures for High-Performance Electrocatalytic Water Splitting.

Developing efficient electrocatalysts is significant for the commercial application of electrocatalytic water splitting. 2D materials have presented great prospects in electrocatalysis for their high surface-to-volume ratio and tunable electronic properties. Particularly, MXene emerges as one of the most promising candidates for electrocatalysts, exhibiting unique advantages of hydrophilicity, outstanding conductivity, and exceptional stability. However, it suffers from lacking catalytic active sites, poor oxidation resistance, and easy stacking, leading to a significant suppression of the catalytic performance. Combining MXene with other 2D materials is an effective way to tackle the aforementioned drawbacks. In this review, the focus is on the accurate synthesis of 2D/2D MXene-based catalysts toward electrocatalytic water splitting. First, the mechanisms of electrocatalytic water splitting and the relative properties and preparation methods of MXenes are introduced to offer the basis for accurate synthesis of 2D/2D MXene-based catalysts. Then, the accurate synthesis methods for various categories of 2D/2D MXene-based catalysts, such as wet-chemical, phase-transformation, electrodeposition, etc., are systematically elaborated. Furthermore, in-depth investigations are conducted into the internal interactions and structure-performance relationship of 2D/2D MXene-based catalysts. Finally, the current challenges and future opportunities are proposed for the development of 2D/2D MXene-based catalysts, aiming to enlighten these promising nanomaterials for electrocatalytic water splitting.

Behavioral toxicity of TDCPP in marine zooplankton: Evidence from feeding and swimming responses, molecular dynamics and metabolomics of rotifers

As new organic flame retardants, chlorinated organophosphate esters (Cl-OPEs) have high water solubility and structural similarity to organophosphate pesticides, posing risks to aquatic organisms. The potential neurotoxicity of Cl-OPEs has attracted attention, especially in marine invertebrates with a relatively simple nervous system. In this study, a marine rotifer with a cerebral ganglion, Brachionus plicatilis, was exposed to tris (1,3-dichloro-2-propyl) phosphate (TDCPP) (two environmental concentrations and one extreme level), and the changes in feeding and swimming behaviors and internal mechanism were explored. Exposure to 1.05 nM TDCPP did not change the filtration and ingestion rates of rotifers and average linear velocity. But 0.42 and 4.20 μM TDCPP inhibited these three parameters and reduced unsaturated fatty acid content, reproduction and population growth. All TDCPP test concentrations suppressed AChE activity, causing excessive accumulation of acetylcholine within rotifers, thereby disturbing the neural innervation of corona cilia. Molecular docking and molecular dynamics revealed that this inhibition was because TDCPP can bind to the catalytic active site of rotifer AChE through van der Waals forces and electrostatic interactions. TRP420 was the leading amino residue in the binding, and GLY207 contributed to a hydrogen bond. Nontargeted metabolomics using LC-MS and GC-MS identified differentially expressed metabolites in TDCPP treatments, mainly from lipid and lipid-like molecules, especially sphingolipids. TDCPP decreased ganglioside content but stimulated ceramide generation and the expression levels of 3 genes related to ceramide de novo synthesis. The mitochondrial membrane potential (MMP) and ATP content decreased, and the electron respiratory chain complex and TCA cycle were deactivated. An inhibitor of ceramide synthase, fumonisin, alleviated MMP and ATP, implying a critical role of ceramide in mitochondrial dysfunction. Thus, TDCPP exposure caused an energy supply deficit affecting ciliary movement and ultimately inhibiting rotifer behaviors. Overall, this study promotes the understanding of the neurotoxicity of Cl-OPEs in marine invertebrates.

Recent Progress in Atomically Dispersed Non‐noble Metal Catalysts for Electrochemical Two‐electron Oxygen Reduction Reaction

AbstractElectrochemical two‐electron oxygen reduction reaction (2e− ORR) has emerged as an efficient route to generate hydrogen peroxide (H2O2) under ambient conditions, being a promising alternative to the traditional energy‐intensive anthraquinone process and direct synthesis route using H2 and O2. However, this 2e− ORR process still requires highly efficient electrocatalysts to adsorb and activate O2 with two‐electron reaction pathway. Among all investigated 2e− ORR electrocatalysts to date, non‐noble metal single atom catalysts (SACs) with tunable electronic structure and different coordination structures manifest great potential in controlling ORR pathway to obtain high‐efficiency H2O2 production. In this review, recent advances and achievements in tuning non‐noble metal SACs for selective 2e− ORR to H2O2 are systematically summarized. Especially, the strategies to effectively regulate the catalytic active sites of non‐noble metal SACs for optimizing the binding strength of key oxygenated intermediates during 2e− ORR are emphatically exhibited and reviewed. Finally, we also point out the challenges and outlooks about the development of non‐noble metal SACs in H2O2 electrosynthesis and the diverse utilization of in‐situ formed H2O2 for biomass upgrading. This review would be helpful to guide the design and development of efficient SACs for electrochemical 2e− ORR to H2O2 under ambient conditions.

Discovery of 5-Hydroxy-1,4-naphthoquinone (Juglone) Derivatives as Dual Effective Agents Targeting Platelet-Cancer Interplay through Protein Disulfide Isomerase Inhibition.

In this study, a series of 2- and/or 3-substituted juglone derivatives were designed and synthesized. Among them, 9, 18, 22, 30, and 31 showed stronger inhibition activity against cell surface PDI or recombinant PDI and higher inhibitory effects on U46619- and/or collagen-induced platelet aggregation than juglone. The glycosylated derivatives 18 and 22 showed improved selectivity for inhibiting the proliferation of multiple myeloma RPMI 8226 cells, and the IC50 values reached 61 and 48 nM, respectively, in a 72 h cell viability test. In addition, 18 and 22 were able to prevent tumor cell-induced platelet aggregation and platelet-enhanced tumor cell proliferation. The molecular docking showed the amino acid residues Gln243, Phe440, and Leu443 are important for the compound-protein interaction. Our results reveal the potential of juglone derivatives to serve as novel antiplatelet and anticancer dual agents, which are available to interrupt platelet-cancer interplay through covalent binding to PDI catalytic active site.

Experimental investigation of integrated CO2 capture and conversion to syngas via calcium looping coupled with dry reforming of CH4

Calcium looping integrated with dry reforming of CH4 is a promising strategy for CO2 capture and in situ conversion to syngas. This intensified process is usually conducted with bifunctional materials that combine CO2 capture (CaO) and catalytic (Ni) active sites. Herein, the integrated calcium looping/dry reforming process was examined by investigating various bifunctional materials and operating conditions. The Ni loading of materials affected the interaction between active and inert phases, while adding a CaZrO3 promoter enhanced the CO2 capture and catalytic activities and the resistance toward sintering. Conducting experiments with a fluidized bed reactor (700 °C, 3% CH4 in feed) led to nearly complete CH4 conversion and ∼52% utilization of captured CO2 toward syngas production with steady H2/CO ratio close to unity. Temperature comprised a decisive parameter, with low values enabling high degrees of CO2 conversion up to ∼80%. The increase of CH4 concentration in the gas feedstock enhanced the rate of calcination and the conversion of CO2 over its desorption in the gas phase. Co-feeding O2 with CH4 was proposed to mitigate the energy demand, which reduced the reforming selectivity for the partial oxidation reaction and increased the H2/CO ratio of syngas.

Cobalt nanoparticles supported on nitrogen-doped carbon nanotubes for the efficient oxygen reduction reaction in Mg-air battery

Fabricating the non-precious-metal catalyst with desirable catalytic performance towards oxygen reduction reaction (ORR) is essential for Mg-air battery that adopts neutral brine electrolyte. However, the classic metal-nitrogen-carbon materials with strong ORR catalytic activity in alkaline solution usually display inferior performance than platinum-based catalysts in neutral environment. Herein, we construct a hybrid catalyst composed of cobalt nanoparticles and nitrogen-doped carbon nanotubes, based on pyrolyzing the mixture of melamine, pyrazole, hexadecyl trimethyl ammonium bromide, and 2-methylimidazole chelated with Co2+ and Zn2+ ions. This catalyst possesses abundant ORR catalytic active sites and mesoporous structure with large pore volume, which can result in the superior performance of Mg-air battery than that using Pt/C catalyst. Furthermore, its ORR catalytic mechanism is unraveled according to microstructure characterization and electrochemical response.

Insights into the role of S-Ti-O bond in Titanium-Based catalyst for photocatalytic CH4 reforming: Experimental and DFT exploration

Given the increasingly severe climate and energy crises, this paper proposes the concept of “room-temperature solar-powered CH4 reforming”, intended to achieve carbon emission reduction and efficiently use carbon-containing resources. However, traditional semiconductors as catalysts have some problems, such as few catalytic active sites and fast recombination of photogenerated electrons and holes, resulting in low efficiency of photocatalytic CH4 reforming. For this reason, a series of doped catalysts X-TiO2 (X = Br, N, and S) are prepared by introducing nonmetallic elements into the TiO2 lattice to construct oxygen defects. Notably, the CO yield of the S-TiO2 catalyst was 1048μ mol g−1, 65 times higher than the catalytic performance of bulk TiO2. Based on the functional density theory (DFT) calculation, the interaction between the S active site and the performance of photocatalytic CH4 reforming with oxygen defects is discussed in detail. The synergistic effect of the S site and the oxygen defect has been shown to rapidly activate C = O and C-H bonds at room temperature. Finally, based on the tracer experiment and DFT calculation, a possible mechanism of photocatalytic CH4 reforming at room temperature is proposed. This work provides a new research direction for achieving carbon neutrality at room temperature and a feasible technical scheme for the large-scale application of photocatalysts.

Allostery in Protein Tyrosine Phosphatases is Enabled by Divergent Dynamics.

Dynamics-driven allostery provides important insights into the working mechanics of proteins, especially enzymes. In this study, we employ this paradigm to answer a basic question: in enzyme superfamilies, where the catalytic mechanism, active sites, and protein fold are conserved, what accounts for the difference in the catalytic prowess of the individual members? We show that when subtle changes in sequence do not translate to changes in structure, they do translate to changes in dynamics. We use sequentially diverse PTP1B, TbPTP1, and YopH as representatives of the conserved protein tyrosine phosphatase (PTP) superfamily. Using amino acid network analysis of group behavior (community analysis) and influential node dominance on networks (eigenvector centrality), we explain the dynamic basis of the catalytic variations seen between the three proteins. Importantly, we explain how a dynamics-based blueprint makes PTP1B amenable to allosteric control and how the same is abstracted in TbPTP1 and YopH.

Unraveling the Impact of Curvature on Electrocatalytic Performance of Carbon Materials: A State-of-the-Art Review.

Curvature of carbon materials has gained significant attention as catalysts due to their distinctive properties and potential applications. This review comprehensively summarizes how the bending of carbon materials can improve electrocatalytic performance, with special attention to the applications of various bent carbon materials (such as carbon nanotubes, graphene, and fullerene) in electrocatalysts and a large number of related density functional theory (DFT) theoretical calculations. Extensive mechanism research has provided a wealth of evidence indicating that the curvature of carbon materials has a profound impact on catalytic activity. This improvement in catalytic performance by curved carbon materials is attributed to factors like a larger active surface area, modulation of electronic structure, and better dispersal of catalytic active sites. A comprehensive understanding and utilization of these effects enable the design of highly efficient carbon-based catalysts for applications in energy conversion, environmental remediation, and chemical synthesis.