Catalysis Science & Technology最新文献

Catalysis Science & Technology, Evgeny Pidko and Núria López would like to acknowledge Weixue Li for their contributions to the Digital Catalysis themed collection as a Guest Editor.

Although TiO₂ has been widely used as an efficient photocatalyst, the photocatalytic active sites remain ambiguous. Using rutile TiO₂(110) surfaces with well-defined defects, we herein unambiguously identify that edge sites on TiO₂ surfaces with interstitial Ti³⁺ defects are photocatalytically active. On the oxidized TiO₂(110) surface with TiO₂ islands, chemisorbed CO₂ and CO are photo-inactive; on the TiO₂(110) surface with surface bridging oxygen vacancies and bulk interstitial Ti³⁺ defects, CO₂ and CO chemisorbed at the vacancy sites become photoactive; on the TiO₂(110) surface with TiO₂ islands and interstitial Ti³⁺ defects, CO₂ and CO chemisorbed at the edge sites of TiO₂ islands are also photoactive. CO chemisorbed at the surface oxygen vacancies shows the highest photo-induced desorption probability, while CO₂ chemisorbed at the edge sites of TiO₂ islands with interstitial Ti³⁺ exhibits the highest photo-induced desorption probability. Considering their abundance on powder TiO₂ photocatalysts, the edge sites are among the photocatalytic active sites contributing to TiO₂ photocatalysis.

The development of regioselective and stereoselective catalytic methodologies marks a significant milestone in green chemistry. With the increasing need for sustainable practices in the chemical industry, these approaches are transforming the synthesis of complex chemical intermediates, including pharmaceuticals, agrochemicals, and functional materials. Catalytic methods make these reactions more selective to given substrates, which increases atom economy while lessening the environmental impact. The objective of this review is to analyze and discuss recent developments in catalysis with an emphasis on sustainable methodologies which include: transition metal catalysis, organocatalysis, photocatalysis, and electrocatalysis. The catalytic approaches not only offer cleaner and more efficient energy pathways for molecular transformations, but also support the use of hydrogen and bio-based feedstocks along with green solvents, adhering to eco-design principles. In academic and industrial settings, precision chemistry is achieved through regio- and stereoselective catalysis. The resulting discrete building blocks reduce the number of steps, resources, and waste necessary to produce the desired molecular structures. The inclusion of circular economy models and life-cycle assessment (LCA) methodologies has made these processes more appealing from a regulatory and industrial standpoint, driving a shift towards sustainable process innovations. Even so, the difficulties of catalyst deactivation, a narrow scope for reusability, limited substrate scope, and economic scalability barriers continue to impede industrial adoption across the field. To resolve these issues, the review suggests future strategies such as the creation of catalysts from earth-abundant metals, the formation of hybrid catalytic systems, AI and machine learning integration for catalyst development, and real-time dynamic optimization of processes through digital chemistry tools. The review also aims to motivate the design of catalytic systems that shift from environmentally irresponsible to sustainable, economically viable, and revolutionize the industry while bridging the gap between innovation and application by outlining achievements alongside existing problems, thus closing the gap between innovation and application.

The non-equilibrium conditions inherent in femtosecond laser ablation in liquids (LAL) offer a versatile platform for synthesizing metastable nanomaterials, yet predicting the structural evolution of complex oxides under rapid quenching remains a challenge. Here, we elucidate the divergent structural and functional outcomes of LAL applied to two related wide-bandgap niobium-based oxides: LiNbO₃ and Nb₂O₅. We find that the intrinsic crystallization kinetics of the materials dictate their response to laser-induced fragmentation and condensation. Nb₂O₅, a strong glass-former with complex polymorphism, is trapped in an amorphous state. In contrast, LiNbO₃ exhibits robust thermodynamic stability, favoring rapid nucleation and growth to form polycrystalline, albeit defect-rich, nanoparticles. These structural differences profoundly impact their electronic landscapes. Amorphization in Nb₂O₅ introduces a broad continuum of localized states that facilitate rapid charge recombination. Conversely, defect engineering in crystalline LiNbO₃ yields discrete mid-gap states that enhance visible-light absorption and prolong carrier lifetimes. Consequently, LiNbO₃ nanoparticles demonstrate sustained hydroxyl radical generation under visible irradiation, achieving a photocatalytic dye degradation rate threefold higher than their amorphous Nb₂O₅ counterparts and enabling 90% dye removal after 150 minutes at low catalyst loading. This investigation underscores the critical role of intrinsic crystallization kinetics in LAL synthesis and establishes defect-mediated crystallinity as a superior strategy over amorphization for activating wide-bandgap materials for solar-driven photocatalysis.

The addition of metal oxides as impurities to generate an intermediary energy band near the conduction or valence band to reduce the bandgap is the most distinctive approach to improve the photo-absorption characteristics of the material. Herein, we have reported the synthesis of nanohybrid bimetallic heterostructures by linking the interface of CeO₂ and CoO, which narrows the electronic band structure of CeO₂ from 2.85 eV to 1.5 eV and modulates the distribution of charges at the active sites. The resulting CeO₂/CoO hybrid support enhances the dispersion and stability of Pd NPs, resulting in lowering the activation energy (E_a) barrier of the coupling reaction, thereby significantly enhancing its catalytic efficacy. The E_a value of CeO₂/CoO/Pd (53.7 kJ mol⁻¹) is much lower compared to that of CeO₂/Pd (68.6 kJ mol⁻¹), with excellent catalytic activities (yield: 98%) and exhibiting long-term stability for 5 continuous cycles without any significant loss in activity. Overall, the CeO₂/CoO/Pd hybrid system effectively utilized the photothermal effect to facilitate an effective electron transfer, thereby enhancing the rate of the Suzuki–Miyaura coupling reaction. This study offers a feasible and encouraging prospect to use the heterostructured metal oxide-based catalytic system for efficient Suzuki–Miyaura cross-coupling reaction.

A useful strategy for the co-polymerization of ethylene and functional olefins relies on palladium catalysts, as palladium typically shows in contrast to many other metals a high tolerance to a variety of functional groups. Here we have prepared a set of palladium complexes containing a N,N-bidentate coordinating bis(pyridinium amidate) (bisPYA) ligand. Ligand variation included either para- or an ortho-pyridinium amidate arrangement, with the pyridinium site either sterically flexible or locked through a dimethyl substitution ortho to the amidate. Activation of these complexes with NaBArF in the presence of ethylene indicated that sterically locked ligand structures promoted ethylene conversion and produced polymeric materials. In particular, complex 4d with an ortho-pyridinium amidate bisPYA ligand was active with a production of 10.8 kg polyethylene per mol palladium at room temperature and 1 bar ethylene. Synthesis of the complexes in the presence of K₂CO₃ or Ag₂CO₃ afforded adducts in which the K⁺ or Ag⁺ ion is bound by the two oxygens of the bisamidate core, thus leading to trimetallic Pd⋯K⋯Pd complexes. Such adduct formation indicates a dual role of NaBArF in halide abstraction and metal sequestration, thus rationalizing the need for 2.5 equivalent of NaBArF per palladium complex for effective polymerization.

The interaction between Cu and Zr is crucial for the performance of Cu-based catalysts in CO₂ hydrogenation. This study compares a series of Cu–Zr catalysts with different Cu–Zr ratios prepared at two flow rates in a microreactor. The structural evolution of the catalysts was investigated using X-ray diffraction (XRD), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and temperature-programmed desorption (CO₂-TPD). It is found that the enhanced mixing in the microreactor improves component dispersion in the Cu–Zr precipitates, leading to smaller CuO crystallite sizes in the calcined oxides and more Cu–Zr interfaces in the reduced catalysts, which thereby exhibit superior catalytic performance. Additionally, superior mixing in the coprecipitation enables the catalyst to achieve abundant Cu–Zr interfaces even at lower Zr content, whereas catalysts prepared under inferior mixing require higher Zr content to establish adequate Cu–Zr interfaces.

Industrial ammonia (NH₃) production is predominantly achieved by the Haber–Bosch process, which consumes substantial energy and emits significant CO₂. The electrochemical nitrate reduction reaction (NO₃RR) presents a promising alternative to the Haber–Bosch process due to its environmentally benign nature. Developing highly active, selective, and stable electrocatalysts for the NO₃RR remains a focal point of contemporary research. In this work, the d-band center of the Cu₁Ni₁@GO catalyst was strategically modulated via an alloying approach, endowing it with balanced adsorption and desorption capabilities for reaction intermediates. This optimization resulted in exceptional performance, achieving an ammonia yield of 3.47 mg h⁻¹ cm⁻² and a Faraday efficiency (FE) of 85.2% at an overpotential of −0.5 V vs. RHE. Theoretical calculations confirmed the d-band center shift in Cu₁Ni₁@GO and its profound influence on intermediate adsorption dynamics and NO₃RR activity, offering crucial insights for the rational design of advanced alloy catalysts. By elucidating the synergistic effect in CuNi @GO composites, this study offers insights for designing efficient catalysts for nitrate reduction to ammonia, with promising applications in sustainable energy and environmental protection.

Bifunctional Zn-modified HZSM-5 catalysts demonstrate excellent catalytic performance in ethylene aromatization. However, they often undergo rapid deactivation owing to the loss of zinc species. Here, we show that the activity of surface zinc species in Zn/ZSM-5 for ethylene aromatization can be enhanced by fine-tuning the synthesis parameters during the preparation of Zn-modified HZSM-5. Specifically, the Zn/ZSM-5 catalyst prepared under weakly acidic conditions exhibited superior anti-carbon deposition and anti-Zn loss properties compared to that prepared under alkaline conditions. We suggest that the reactivity of surface zinc species for ethylene aromatization was enhanced because of the formation of a hexacoordinated ZnOH⁺ species structure, which serves as the catalytic active center to facilitate dehydrogenation, thereby exhibiting a positive correlation with the catalyst's aromatization performance.

The extreme toxicity of nerve agents highlights the urgent need for catalytic materials that can operate under realistic, dry conditions. Zirconium-based MOF-808 is effective for the aqueous-phase hydrolysis of these agents, but its performance drops sharply in solid-phase environments due to poisoning by tightly bound bidentate products. Here, we introduce a manganese (Mn) single-atom modified version of MOF-808 that overcomes this limitation. Unlike the native framework, Mn@MOF-808 achieves catalytic turnover (turnover number or TON > 1) for nerve agent and simulant degradation under ambient, unbuffered, and solvent-free conditions. The Mn sites help avoid product inhibition by favoring monodentate interactions over bidentate coordination. Experimental results show sustained reactivity during degradation of sarin and its simulants, and DFT calculations support reduced desorption energies of bound products. This work marks the first example of a MOF-based catalyst demonstrating turnover in solid-phase nerve agent degradation and moves a step closer to practical chemical threat mitigation.