查找使用阿拉丁产品的科研文献

Synergistic CO2 hydrogenation with DBD plasma over a Ni-based catalyst prepared at low temperature

Qian Zhang,Yi Chen,Miaomiao Xiao,Xin Zhang,Langlang Wang,Xiang Li,Xin Sun,Kai Li,Ping Ning,Yixing Ma,Xueqian Wang

The integration of non-thermal plasma (NTP) with supported metal catalysts presents a promising strategy for the conversion of carbon dioxide under mild conditions. This study prepared catalysts at relatively low temperatures and employed dielectric barrier discharge (DBD) plasma to drive CO 2 hydrogenation under low-temperature reaction conditions. The optimization effect of CeO 2 loading on the performance of Ni/ZSM-5 catalysts was systematically investigated. The results indicate that the 15Ni-15Ce/ZSM-5 catalyst exhibits the most optimal performance. At a specific energy input (SEI) of 21.65 kJ/L, the CO 2 conversion rate reaches 88.6%, representing a more than fourfold improvement over the 15Ni/ZSM-5 catalyst. The selectivities for CH 4 , C 2 H 6 , and C 3 H 8 are 90.4%, 6.8%, and 2.0%, respectively. Characterization revealed that optimized low-temperature preparation conditions successfully generated highly dispersed metallic Ni 0 active sites. The introduction of CeO 2 further reduced Ni 0 particle size and created abundant oxygen vacancies. The 15Ni-15Ce/ZSM-5 catalyst enhances CO 2 adsorption and activation through oxygen vacancy-enhanced mechanisms, while NTP generates active H atoms from H 2 . Both processes synergistically drive efficient reaction progress. In situ DRIFTS analysis of surface species on 15Ni/ZSM-5 and 15Ni-15Ce/ZSM-5 catalysts under NTP conditions revealed the mechanism of NTP-catalyzed CO 2 methanation. Results indicate that hydrogenation on 15Ni/ZSM-5 primarily follows the CO pathway. After the introduction of CeO 2 , the reaction pathway changes, with the 15Ni-15Ce/ZSM-5 catalyst achieving highly selective hydrogenation mainly through the b-HCOO pathway.

Template-Free One-Pot Synthesis of Ni-Beta Zeolites: Protonation Modulation for Boosted Methanol Electrooxidation

Mingzi Sun,Wenzhuo Liu,Yun Li,Jilin Cao

Developing high-performance non-precious metal catalysts for the methanol oxidation reaction remains a challenge for direct methanol fuel cells. Herein, a nickel-doped Beta (Ni-Beta) zeolite was successfully synthesized via a template-free one-pot hydrothermal route followed by protonation via ammonium exchange. In this work, the protonation process strengthened metal–support interaction to form Ni2+/Ni3+redox pairs, introduced abundant acidic sites, and optimized the zeolitic pore structure. Optimized Ni-H-Beta-170 (Si/Ni = 170) achieved a remarkable mass activity of 71.6 A g−1at 0.66 V vs. Hg/HgO, around 10-fold higher than unprotonated Ni-Beta zeolite. The improved activity originates from reversible Ni2+/Ni3+cycles for eliminating toxic COads, enriched acid sites accelerating C–H cleavage of methanol and formation of active NiOOH, and enlarged pore volume facilitating mass transfer. This work offers a low-cost strategy toward advanced non-precious methanol oxidation reaction electrocatalysts.

Enhancement of wear and acid corrosion protection in Ni-W-P/TiB2@PANI composite coating

Mier Bai,Han Liu,Zhenyu Li,Yi He,Shijun Xu,Qing Yuan,Yi Sun,Xiangshan Hou

This study employs a low-temperature oxidation self-polymerization method to prepare polyaniline-coated titanium diboride (TiB 2 @PANI) composite materials and co-deposited them with the Ni-W-P system to fabricate a Ni-W-P/TiB 2 @PANI composite coating. This coating's microstructural features, mechanical characteristics, and anti-corrosive properties are systematically investigated. Experimental results demonstrate that the addition of TiB 2 @PANI reduced the average coefficient of friction (COF av ) of the composite coating from 0.560 to 0.232, while the impedance (R t ) represented an approximate 20-fold increase over the pristine Ni-W-P matrix. The SEM and XRD results indicate that TiB 2 @PANI effectively inhibits coating corrosion failure and enhances the improved early-stage corrosion resistance of the coating during a 72 h immersion test in a 0.1 mol/L H 2 SO 4 solution at 40°C.

Pressure-driven reconstruction of single-atom Ni-O-K interface for near-equilibrium CO2 hydrogenation

Wendong Wang,Fangsong Guo,Longmei Shang,Kang Sun,Dandan Song,Jianchun Jiang,Guowu Zhan

Pressure-driven reconstruction forms Ni-O-K single-atom interfaces. • Near-equilibrium CO 2 conversion (∼58%) with ∼100% CO selectivity. • Exceptional stability over 200 h without sintering or deactivation. • Ni-O-K sites lower E a and suppress methanation. • Carboxyl pathway dominates over formate route. Achieving simultaneous high activity, selectivity, and stability in single-atom catalysts (SACs) under high-temperature conditions remains a significant challenge, primarily due to the difficulty in precisely controlling the coordination environment of metal centers. Here, we demonstrate that alkali ion (e.g., K + ) modification of both Ni single atoms and their carbon nitride (CN) support enables exceptional performance in the reverse water-gas shift (RWGS) reaction. The resulting Ni@K-CN catalyst achieves near-equilibrium CO 2 conversion with nearly 100% CO selectivity across a broad temperature range (400–600 ℃), alongside remarkable long-term stability. This performance substantially surpasses that of the K-free analogue and ranks among the best-reported non-noble metal RWGS catalysts. Operando studies reveal that the catalyst undergoes a thermodynamically driven in-situ reconstruction under high pressure reaction conditions, forming atomically dispersed Ni-O-K interfacial sites within a restructured carbon nitride matrix. Density functional theory calculations reveal that these sites markedly lower the apparent activation energy ( E a = 41.5 vs. 131.4 kJ·mol −1 ), modulate the electronic structure of Ni and surface-adsorbate interactions, and thereby promote a low-energy-barrier carboxyl pathway while kinetically suppressing methanation. This work establishes a design strategy based on alkali-mediated dynamic reconstruction to create highly stable and selective SACs for demanding high-temperature catalytic processes. Download: Download high-res image (174KB) Download: Download full-size image

Oxygen vacancy engineering in hollow confined Ni/CeO2 nanofibers for steering intermediates in CO2 methanation

Longmei Li,Feiyang Hu,Xiuxing Cai,Tingrui Zeng,Qing Liu,Runping Ye,Lei Gong,Rongbin Zhang,Gang Feng

Uniformly dispersed and confined hm-Ni/CeO 2 catalysts were synthesized for CO 2 hydrogenation. • The hm-Ni/CeO 2 outperforms its mesoporous counterpart, reaching 84.56% CO 2 conversion at 325 °C with good stability. • The hm-Ni/CeO 2 possesses abundant oxygen vacancies and a higher Ni distribution. • In-situ DRIFTS and DFT studies confirmed that the enhanced methanation performance originates from oxygen vacancies promoting the formate pathway. Confined structure catalysts are widely dedicated to boosting catalytic activity and stability , while controlling their micro-environment and intermediate species remains a challenge. Herein, mesoporous (m-Ni/CeO 2 ) and hollow mesoporous (hm-Ni/CeO 2 ) catalysts were prepared via electrospinning and evaluated for CO 2 hydrogenation to methane. The hm-Ni/CeO 2 catalyst exhibits superior performance, achieving 84.56% CO 2 conversion at 325 °C, along with enhanced low-temperature activity compared to the m-Ni/CeO 2 catalyst. Characterizations revealed that the hm-Ni/CeO 2 catalyst possesses a higher oxygen vacancies and improved Ni dispersion, thereby enhancing metal-support interaction. Furthermore, synchrotron radiation and in-situ DRIFTS confirmed that the hm-Ni/CeO 2 catalyst facilitates the formation of bridging bidentate formate intermediates, which are more favorable for CH 4 production. Finally, DFT verified the predominance of the formate pathway and revealed that oxygen vacancies substantially enhance the reactivity of CO 2 methanation. This work not only develops a novel synthetic strategy for confined porous catalysts but also provides fundamental insights into the role of oxygen vacancies in CO 2 hydrogenation. Download: Download high-res image (203KB) Download: Download full-size image

Ni Single Atoms and Prussian Blue Analogs Comodified Poly(heptazine imide) for Efficient CO2 Photoreduction

Tianyu Tang,Guowei Wang,Yitong Wang,Xin Jiang,Zhijun Li,Cailing Chen,Ziqing Zhang,Liqiang Jing

Poly(heptazine imide) (PHI) has garnered significant attention as a promising material for photocatalytic CO2 reduction. However, its practical application is hindered by limitations stemming from inefficient electron-mediated reduction processes and sluggish hole-driven oxidation kinetics. Herein, the Ni single atoms and hollow CoFe Prussian blue analogs were precisely decorated on PHI (CoFePBA@Ni-PHI) through a two-step calcination and in situ ion exchange-growth conversion process. The optimized CoFePBA@Ni-PHI photocatalyst demonstrates a superior CO evolution rate of 41.3 μmol g–1 h–1 in pure water without sacrificial agents, representing a 4.5-fold and 5.7-fold enhancement compared to pristine PHI and g-C3N4, respectively. The enhanced photocatalytic performance is primarily ascribed to the synergistic redox dual-site modification, where Ni single atoms serve as electron extractors to promote CO2 reduction, while hollow CoFePBA functions as hole-trapping sites to facilitate water oxidation, thereby collectively accelerating the overall photocatalytic process. This work elucidates the critical role of dual redox site engineering in photocatalytic systems and provides a rational design strategy for constructing efficient photocatalysts toward solar-driven fuel production.

Non-Noble Metal Ni/NiOx@C Co-Catalyst Modified ZnIn2S4 for Efficient Photocatalytic Hydrogen Production

Photocatalytic hydrogen production has emerged as one of the most promising approaches for addressing the global energy crisis by enabling the sustainable conversion of solar energy into clean hydrogen fuel. However, its practical application is still hindered by the rapid recombination of photogenerated electron–hole pairs, which severely limits photocatalytic efficiency. Although noble-metal co-catalysts have been demonstrated to markedly promote charge separation and accelerate surface reaction kinetics, their widespread application remains constrained by their high cost and limited availability. In this study, a non-noble Ni/NiOx@C co-catalyst was fabricated and employed to modify ZnIn2S4(ZIS) for photocatalytic hydrogen production. The optimized sample (15Ni/NiOx@C/ZIS) exhibits a hydrogen production rate of 4140.03 μmol/g/h, 18.16 times higher than that of pristine ZIS. This enhancement is primarily attributed to the improved separation and transfer of photogenerated charge carriers facilitated by the Ni/NiOx@C co-catalyst. Notably, the hydrogen evolution rate of 15Ni/NiOx@C/ZIS is 1.33 times higher than that of ZIS/3%Pt, suggesting that Ni/NiOx@C has great potential as a substitute for noble metal Pt. Various characterization results demonstrate that 15Ni/NiOx@C/ZIS exhibits superior photocatalytic performance, ascribed to its enhanced light absorption capability, and efficient separation of photogenerated carriers. Additionally, cycling tests and XRD analysis confirm the excellent stability of 15Ni/NiOx@C/ZIS, indicating its potential for practical applications. This work provides a valuable reference for the rational design and development of efficient and cost-effective non-noble co-catalysts for photocatalytic hydrogen production.

Synergistic Ti-Ni co-doping enhances the electrochemical performance and densification of LiMn0.6Fe0.4PO4/C cathodes

Long Ye,Juntao Si,Cheng Zhang,Sihan Zeng,Chunhua Chen

Ti-Ni co-doping improves electrochemical kinetics and powder densification. • Dopants Ti and Ni function on the Mn- and Fe-redox regions, respectively. • Powder compaction density increases by 8.5% to 2.04 g cm −3 after Ti-Ni doping. LiMn 0.6 Fe 0.4 PO 4 (LMFP) is a promising high-energy cathode, but its practical application is constrained by sluggish Mn 2+ /Mn 3+ redox kinetics and insufficient powder compaction density (PCD). Herein, Ti-doped, Ni-doped, and Ti–Ni co-doped LMFP/C were prepared by a ball-milling-assisted solid-state route. It is clarified that Ni predominantly accelerates the Fe 2+ /Fe 3+ reaction, whereas Ti promotes the kinetically slower Mn 2+ /Mn 3+ reaction and improves cycling stability. The optimal sample LMFP-2Ti-2Ni delivers 163.1 and 142.9 mAh g −1 at 0.1 and 5 C, respectively, and retains 90.8% of its capacity after 400 cycles at 1 C. Relative to pristine LMFP, the Ti-Ni co-doping increases the 0.1 C capacity from 144.7 to 163.1 mAh g −1 (+12.7%) and the PCD from 1.88 to 2.04 g cm −3 (+8.5%). Also, the relative unit-cell-volume variation decreases from approximately 5.2% to 4.6%, indicating more gradual bulk-lattice evolution. Thus, Ti–Ni co-doping as a complementary strategy can simultaneously improve rate capability, cycling durability, and particle packing in LMFP/C cathodes. Download: Download high-res image (356KB) Download: Download full-size image

Ni/Co Bimetallic Nanoparticles on Co3O4 Nanoarrays Bridged by CNTs for High Oxygen Evolution Reaction

Tao Wang,Qiudi Zhang,Xupeng Zhu,Mengjie Zheng,Xinshui Zhang,Jing Wang,Haiqin Bian,Zhengmei Zhang,Jun Zhang,Huimin Shi

Herein, we report a high-performance electrocatalyst for the lattice-oxygen-mediated (LOM) alkaline oxygen evolution reaction (OER), a key process for green hydrogen production. By employing a simple solvothermal and chemical vapor deposition (CVD) approach, we successfully synthesized CNT-bridged Ni/Co bimetallic nanoparticles on a Co3O4 nanoarray matrix supported by nickel foam (NF). The in situ grown CNTs and Ni/Co nanoparticles introduce abundant oxygen vacancies (Ov), significantly lowering the Gibbs free energy (ΔG) of *OOH desorption and enhancing the OER kinetics. Additionally, edge dislocations in Co nanoparticles induce lattice distortion and strain modulation, optimizing electron transfer and boosting catalytic efficiency and stability. As a result, the Ni/Co-CNTs-Co3O4/NF electrocatalyst achieves an ultralow overpotential of just 133 mV at 10 mA cm–2, maintaining structural integrity and excellent stability over 72 h at 20 mA cm–2. Theoretical calculations further confirm that Ni/Co nanoparticle incorporation tunes the d-band center, facilitating the adsorption–desorption balance of oxygen-containing intermediates and accelerating the OER process. When integrated into an alkaline electrolyzer, the Ni/Co-CNTs-Co3O4/NF electrodes demonstrate a remarkably low operating voltage of 1.58 V at 10 mA cm–2 and impressive durability for over 24 h at 20 mA cm–2. These findings highlight the strong potential of the Ni/Co-CNTs-Co3O4/NF electrocatalyst for the application of scalable, high-efficiency water splitting technology.

Modulating the Interfacial Energy of Ni–Bi Molten Alloys for Enhanced Methane Decomposition to Hydrogen

Zhao Sun,Bin Wang,Nicholas F. Dummer,Haifeng Qi,Louise R. Smith,Zhiqiang Sun,Graham J. Hutchings

Catalytic methane decomposition is a highly promising CO2-free hydrogen production technology with carbon material generation; however, developing catalysts that can efficiently decompose methane at moderate temperatures remains challenging. In this study, we develop a series of NiMn–Bi molten alloy catalysts with various Ni:Mn ratios for catalyzing methane decomposition. The Mn-modified Ni–Bi alloy exhibits a CH4 conversion of 15.3% at 850 °C, and the corresponding hydrogen production rate increases by 112% compared with Ni–Bi. The ternary alloy catalyst also demonstrates stability at this production rate for up to 80 h. Molecular dynamics simulations show that the introduction of Mn significantly reduces the strong interaction between the active metal Ni and the solvent metal Bi, thereby accelerating the methane dissociation rate. More importantly, among the theoretically calculated binding energy, interfacial energy, Ni–Bi interaction, and mean-square displacement, interfacial energy, a comprehensive demonstration of surface energy and atomic interactions, is proposed as a potential descriptor for predicating and estimating the catalytic performance of the molten alloy-based catalysts.

Ni-Doped MoS2/N-Doped Carbon Hollow Nanostructures for Sodium-Ion Half and Full Batteries

Songya Cui,Jiashuo Wang,Chengxiang Tian,Xiaoyu Xu,Dongxue Han,Guang Chen,Yufeng Yu,Liang Peng

Sodium-ion batteries (SIBs) are restricted in their energy storage capacity primarily because the considerable size of Na+ and inherently slow redox processes limit efficient charge transfer. Transition metal chalcogenides with layered structures have considerable promise as advanced materials of SIBs. Herein, the Ni-doped hollow MoS2/NC spheres with nitrogen-doped carbon are fabricated by a simple water/ethanol system combined with thermal annealing. Nickel doping effectively modifies the electronic properties of MoS2, leading to a substantial improvement in electrical conductivity and an increase in the density of electrochemically active sites. The addition of nitrogen-doped carbon within the composite helps to improve redox kinetics, ensuring improved structural integrity. Consequently, the Ni-MoS2/NC anode demonstrates excellent cycling stability, delivering a capacity of 176 mAh g–1 at 5.0 A g–1 for 10,000 cycles. Moreover, a full battery paired with a Na3V2(PO4)3/C cathode exhibits impressive rate performance, when the current is restored to 0.1 A g–1, and it showed a high specific capacity of 326 mAh g–1, which indicates that the Ni-MoS2/NC||Na3V2(PO4)3/C full battery exhibits robust performance across varying current densities, maintaining high electrochemical reversibility. This effective approach ensures improved electrochemical performance, prolonged cycling life, and higher efficiency, making hollow nanostructures a promising design for next-generation energy storage systems.

Highly stable and coking resistant Ce promoted Ni/SiC catalyst towards high temperature CO methanation

Shu-Sen Liu,Yong-Yong Jin,Yahong Han,Jinxian Zhao,Jun Ren

It is a big challenge to improve the stability and anti-coking abilities of catalyst in high temperature CO methanation reaction. To address the issue, SiC was chose as the support, and Ce was used as a promoter to prepare supported Ni catalysts for CO methanation. A long-term high temperature stability evaluation experiment was carried out at 600 °C for 100 h in comparison with Ni/Al 2 O 3 catalyst. The catalysts were characterized by a combination of characterization techniques for understanding the catalytic performance and carbon deposition behaviors in CO methanation. The life test result indicates that, compared to Ni/Al 2 O 3 , Ni/SiC is thermally stable and highly resistant to carbon deposition . Improved cataytic activity and stability was further reached by introduce of Ce promoter into Ni/SiC, which can be attributed to the enhanced interaction between Ni and SiC and improved dispersion of Ni active species.