Catalysis Science & Technology最新文献

Methanol (MeOH) emerges as a cost-efficient hydrogen vector, enabling distributed on-demand hydrogen production to overcome energy storage costs and low-value outputs in green hydrogen systems, yet renewable-powered electrolysis faces volatility-induced economic hurdles. Here, we propose a paradigm-shifting strategy: storage-free prioritized operation with in situ acid–base neutralization for methanol electrolysis. Leveraging real-world wind–solar complementary power data from Shandong Province, a mixed-integer linear programming model integrates electricity volatility, market dynamics, and reactor response. Crucially, energy storage exhibits negative economic effects-eliminating it reduces the levelized cost of hydrogen (LCOH) by 13.8% to 13.54 USD per kg H₂. The integration of formate co-production via electrolyte neutralization triples the internal rate of return (IRR) from 9.6% to 21.7%, achieving a 116.4% return on investment. More importantly, sensitivity analysis identifies methanol pricing as the dominant economic lever: a 10% price decrease slashes LCOH by 0.3 USD per kg H₂, exhibiting 2-fold higher sensitivity than the electrolyzer (EC) price fluctuations. This work redefines distributed hydrogen economics by optimizing the green electricity–methanol–hydrogen–chemical chain.

Three novel cobalt-based complexes, Co(HBTC)_0.5(4,4′-bipy)Cl (1), Co(HBTC)_0.5(4,4′-bipy)Cl/PC (1/PC), and Co(HBTC)_0.5(4,4′-bipy)Cl/NS (1/NS), were prepared with porous carbon (PC) and nano silica (NS) to enhance catalytic and energy storage durability and reusability. (1)/PC exhibited outstanding catalytic efficiency in methyl orange (MO) reduction, maintaining over 119 cycles with a TON of 38.2 mg MO per mg catalyst. Conversely, (1) showcased superior reduction capacity for methylene blue (MB), sustaining 41 cycles with a TON of 12.96 mg MB per mg catalyst. Structural analysis revealed that (1) exhibits high crystallinity, whereas the incorporation of PC and NS results in diminished diffraction intensities. Raman spectroscopy identified carboxylate bonds, while XPS confirmed the presence of Co(II) oxidation states. Thermal analysis indicated a gradual ligand loss, influencing the robustness of the framework. The (1)/PC electrode exhibited outstanding electrochemical behavior in 2 M KOH, delivering a high specific capacitance of 856.4 F g⁻¹ at 1 A g⁻¹ and retaining 88.84% of its initial capacitance after 3300 cycles. Cyclic voltammetry confirmed faradaic charge-storage contributions, while charge–discharge analysis indicated rapid ion diffusion and better surface area. These features, arising from the synergistic integration of porous carbon with abundant electroactive sites, highlight (1)/PC as a promising candidate for advanced supercapacitor applications. This study establishes (1)/PC as a promising multifunctional material for both environmental remediation and advanced energy storage, paving the way for future applications in sustainable technologies.

Two Pd(II) complexes (3a and 3b), with N-bound triazolyl-pyridine ligand structures, were designed and prepared for the C-2 arylation of azoles using aryl iodides and bromides. These Pd(II) complexes feature bidentate N-bound triazolyl-pyridine ligands, as confirmed via single-crystal X-ray diffraction analysis. Among them, the novel [κ²N] (bpmtmp)PdCl₂ complex (3a) demonstrated high catalytic efficiency in the C-2 arylation of substituted benzothiazole and benzoxazoles with various aryl iodides and bromides, using Ag₂CO₃ as a co-catalyst and HFIP as the solvent under ambient conditions. Relatively, the higher (ca. 6%) %V_bur of complex 3a compared to 3b supports its superior catalytic performance in the described reaction. This developed methodology was effectively utilized for the synthesis of the PMX-610 antitumor agent (6m) and demonstrated high catalytic reactivity in C-arylation of 2,2′-bipyridine. We have performed several experiments for the establishment of a plausible reaction pathway. The H/D exchange experiment and the parallel kinetic isotope experiment support that the C–H bond activation of azoles is not the rate-determining step. X-ray photoelectron spectroscopy (XPS) analysis of the intermittent reaction mixture further supports the functioning of a Pd(0) to Pd(II) catalytic cycle.

Replacing the kinetically demanding O₂ evolution reaction (OER) in photoelectrochemical (PEC) water splitting with the anodic oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), a key building-block chemical for polymer synthesis, offers a compelling strategy to improve both process efficiency and economic viability of solar-driven H₂ production. Although thermodynamically more favourable than the OER, direct HMF conversion is hindered by sluggish kinetics and high overpotential requirement, often necessitating redox mediators such as TEMPO to facilitate the conversion, which however introduces extra cost, process complexity and safety concerns. This study demonstrates that a Ni(OH)₂ nanoweb, electrodeposited on BiVO₄, functions as an effective solid-state redox mediator via photo-induced formation of NiOOH for PEC HMF oxidation. 48 hours of prolonged operation confirmed the formation of FDCA along with oxidation intermediates. Kinetic analysis revealed an apparent activation energy of 17.2 kJ mol⁻¹ for HMF oxidation by NiOOH, significantly lower than that of conventional thermocatalytic processes. The Ni(OH)₂ coating also mitigated photocorrosion of BiVO₄, showing excellent stability of the heterostructured photoanode. These findings highlight the dual functionality of the electrodeposited Ni(OH)₂ as both a redox mediator for HMF oxidation and a protective layer for the photoelectrode, offering a stable and cost-effective alternative to existing PEC organic valorisation processes.

Photocatalytic nonoxidative coupling of methane (NOCM) is a meaningful route to obtain multicarbon compounds but faces considerable challenges due to the inertness of methane and poor C–C coupling ability of active sites. Herein, we report an FeO_x cluster-decorated TiO₂ photocatalyst for an efficient photocatalytic NOCM reaction. The results show that decoration of FeO_x clusters over TiO₂ enables adsorption of CH₄ to proceed without thermodynamic limitation, thus being conducive to the conversion of CH₄. Besides, FeO_x clusters contribute to stabilizing lattice oxygen via increasing the bonding energy barrier between *CH₃ and lattice oxygen, thus alleviating the formation of CO₂ and ultimately improving C₂H₆ selectivity. The optimized 0.2FeO_x/TiO₂ exhibits a high C₂H₆ generation rate of 91.0 μmol g⁻¹ h⁻¹ (16.9 times that of bare TiO₂) with a C₂H₆ selectivity of 81.7%. The outcome is meaningful for the design and fabrication of low-cost photocatalysts with high catalytic performance for the photocatalytic NOCM reaction.

The electrochemical reduction of CO₂ (CO₂RR) offers a promising route for sustainable fuel and chemical production. This study compares the CO₂RR performance of hydrothermally synthesized carbon nanosphere-supported nickel hydroxide (Ni–C), copper hydroxide (Cu–C), and bimetallic nickel–copper hydroxide (NiCu–C) catalysts, investigating the influence of metal composition. Significant differences in product selectivity were observed: Cu–C primarily yielded C₂ products, whereas Ni–C and NiCu–C generated mixtures of H₂, CO, formate, and acetate, with minimal C₃ products. Faradaic efficiencies (FEs) for C₃ products (including propylene, propane, and n-propanol) were very low for Ni–C and NiCu–C (<0.3% combined). In comparison, Cu–C showed modest FEs (∼3–5%) primarily for n-propanol. X-ray photoelectron spectroscopy revealed partially oxidized nickel species (Ni^δ+) in Ni–C and NiCu–C and predominantly Cu(I) species post-reaction, while scanning electron microscopy confirmed a distinct fibrous morphology for the Ni-containing catalysts. Control experiments with CO and acetate, and in situ Raman spectroscopy, suggest reaction pathways that differ from the typical Cu-catalyzed routes, potentially involving hydrogenated intermediates such as *CHO. This work provides a comparative analysis, highlighting how catalyst composition and associated electronic/structural properties influence the overall CO₂RR activity and selectivity pathways in Ni, Cu, and NiCu hydroxide systems, rather than achieving significant C₃ production.

IrRu nanoparticles surrounded by Ir/Ru–N–C retain 91.68% of the initial current density at 0.1 V vs. RHE toward acidic hydrogen oxidation reaction in the presence of 1000 ppm CO/H₂, closely correlated with the removal of CO via the following reaction: CO_ad–IrRu nanoparticle + OH_ad–Ir/Ru–N–C → COOH_ad.

During the methanol-to-propylene (MTP) process, the catalytic performance of zeolite catalysts is closely related to its pore structure and acid property. Exploring the structure–function relationship is of great significance for both academic research and industrial applications. In the present work, a series of hierarchical ZSM-11 zeolites with different SiO₂/Al₂O₃ ratios were synthesized by changing the chemical composition of gel precursors. XRD, SEM, TEM, N₂ adsorption–desorption, NH₃-TPD, ICP-OES, NMR spectroscopy, FT-IR spectroscopy, pyridine-IR spectroscopy, in situ UV/vis spectroscopy and TG-DTG analysis were used to explore the structural and textural properties of the as-synthesized zeolite samples. The results show that the change in the SiO₂/Al₂O₃ ratio in the gel precursors has some effects on the morphology, crystalline sizes and porous structural properties of the samples. Furthermore, it plays an important role in tailoring the distribution of the framework Al species and thus in adjusting the acid sites of the as-prepared ZSM-11 catalysts. The distribution of framework Al species in the intersecting cavity significantly decreases with the increased SiO₂/Al₂O₃ ratio in the gel precursors, which inhibits the reaction paths based on the aromatic cycle, resulting in a reduction of aromatic products and carbon deposition precursors while enhancing the selectivity of the targeted product propylene. Typically, as compared with the low-silicon ZSM-11-60, the relatively high-silica ZSM-11-160 exhibits superior catalytic performance to achieve a high selectivity of propylene in the final products (39.4% vs. 17.6%) and a longer catalytic life (106 h vs. 42 h) because of a low coking deposition rate (0.52 mg g⁻¹ h⁻¹vs. 2.21 mg g⁻¹ h⁻¹) during the MTP process.

A series of Ru–Mn catalysts supported on desilicated ZSM-5 (RuMn/ZS) are prepared and investigated for the oxidation of HMF to FDCA under aqueous conditions without an external base. RuMn/ZS shows a two-fold higher catalytic activity than Ru–Mn supported on the parent ZSM-5 (RuMn/HZ), giving the highest FDCA yield of 76.7% under optimised reaction conditions. N₂-sorption analysis indicates that RuMn/ZS possesses a 1.22 times higher total surface area (448 m² g⁻¹) and 2.72 and 6.72 times higher mesopore surface area (207 m² g⁻¹) and mesopore volume (0.942 cm³ g⁻¹) than the parent RuMn/HZ due to the desilication. High-resolution transmission electron microscopy (HRTEM) and elemental mapping indicate that RuMn/ZS possesses relatively smaller particle sizes (1.7 nm) with high dispersion of Ru and Mn. NH₃ and CO₂-temperature programmed desorption studies show that RuMn/ZS has a 2 times higher amount of total acidic sites and a 1.79 times higher amount of total basic sites compared to RuMn/HZ. In addition, RuMn/ZS also possesses a balance ratio of acidic to basic sites (3.08) with optimal amounts compared to other catalysts employed in this study. Furthermore, an in situ diffuse reflectance infrared Fourier transform (DRIFT) study using ammonia, pyridine, and CO₂ as probe molecules discloses that RuMn/ZS possesses relatively stronger Lewis acidic sites and stronger basic sites than RuMn/HZ. HMF adsorbed RuMn/ZS diffuse reflectance ultraviolet-visible and DRIFT spectra substantiate the stronger Lewis acidity and basicity than those of RuMn/HZ. Poisoning studies with additives, such as KSCN, further substantiate the crucial primary role of Lewis acidic sites in efficiently catalysing the HMF oxidation reaction. RuMn/ZS is recyclable for three runs with no notable activity loss.

The integration of adsorption and photocatalysis in heterojunction composites offers a promising strategy for efficient azo dye degradation. Here, a novel α-Fe₂O₃/perylene-3,4,9,10-tetracarboxylic diimide (PDINH) Z-scheme heterojunction was synthesized via a facile solvent method, showcasing synergistic adsorption–photocatalysis for wastewater treatment. Zeta potential analysis (α-Fe₂O₃: +14.7 mV; PDINH: −24.3 mV at pH 5.0) and density functional theory (DFT) calculations (binding energy: −3.10 eV) revealed strong electrostatic interactions between α-Fe₂O₃ and PDINH, enabling uniform nanoparticle dispersion and forming a heterostructure with enhanced specific surface area. Electrochemical measurements confirmed that the Z-scheme heterojunction significantly accelerated charge carrier migration and suppressed electron–hole recombination, facilitated by an internal electric field from well-matched band alignment. Under visible light, the α-Fe₂O₃-15/PDINH composite achieved 93.4% removal of methyl orange (MO), outperforming PDINH alone (63.1%) due to its positive surface charge (+8.7 mV at pH 5.0) that enhanced selective adsorption of anionic dyes. Quenching experiments identified h⁺, ·O₂⁻, and ·OH as the primary reactive species, with the Z-scheme pathway retaining strong redox capabilities for efficient degradation. Notably, the composite exhibited an operational cost of $2.41 per ton, significantly lower than other reported processes, and maintained high efficiency (81.8% MO removal) over multiple cycles. This work demonstrates that the α-Fe₂O₃/PDINH composite integrates adsorption and photocatalysis synergistically, providing a low-cost, scalable solution for azo dye wastewater treatment with potential for industrial application.