Industrial Catalysis Research Articles

Bacteria-Triggered Mineralization of Silica Shells with Nanochannels for Biocatalysis in Harsh Conditions.

Biocatalytic processes using microorganisms are considered efficient and economically and environmentally friendly reactions. However, the viability and function of these microorganisms are prone to being hindered by various practical environments. Here, we reported a bacteria-induced nanochannel structure that endowed the microorganism with biocatalytic ability in harsh conditions. We revealed that the bacteria could trigger the fusion of silica nanoparticles on their surface by the secreted alkaline metabolite, resulting in silica shells with nanochannels on bacteria (bacteria@nSiO2). The nanochannel structure in silica shells endowed bacteria with biocatalytic ability in multiple harsh conditions. We revealed that these nanochannels could influence the mass transfer from the extracellular to the intracellular environment, which protected the bacteria from excessive toxic substance while preserving the mass exchange during biocatalysis. This feature ensured bacteria@nSiO2 with efficient bioactivity under harsh conditions for industrial catalysis and degradation of pollution, which cannot be achieved by corresponding native bacteria. Using the crude oil spill as a practical example, we presented that bacteria@nSiO2 could degrade highly concentrated crude oil, which any reported bacteria cannot achieve. This work emphasized the role of nanochannels in the regulation of cellular functions for enhanced biocatalysis. It also demonstrated a bacteria-triggered nanostructure formation, which is a promising methodology for nanotechnology and provides a strategy for more advanced organism-material hybrids.

A DFT Study of Adsorption of Keto Alcohol Oil on a WO3 (001) Surface Modified with Silver Clusters of Specific Size

AbstractThe essential raw materials, cyclohexanol and cyclohexanone, are derived from the selective catalytic oxidation of cyclohexane. Due to their closely matched boiling points, the efficient separation among the components remains a significant challenge in industrial catalysis. In this work, we employed DFT calculations to explore the adsorption behavior of CyH, CyOH, and Cy═O, on both clean and Ag‐modified ɦ‐WO3 (001) surfaces. The calculation results reveal that Ag4 exhibits the highest stability on the ɦ‐WO3 (001) surface. The organic species adsorbed onto the Agn‐WO3 surfaces through distinct host‐guest interactions: CyH via CH···Ag, CyOH, and Cy═O via HO···Ag and C═O···Ag, respectively. The optimal separation efficacy of CyOH and Cy═O on the Ag2‐WO3 surface results in CyOH as the preferred product, while on the Ag4‐WO3 surface, Cy═O serves as the ultimate outcome. Our theoretical calculations provided in this study offer a valuable theoretical foundation for the separation of the KA oil mixture.

Application of continuous stirring tank reactor for controllable synthesis of Cu7S4 nanocrystals

As a typical model for a chemical reactor in industry, the continuous stirring tank reactor has been widely used in waste-water treatment, industrial catalysis, and biological fermentation as well as great application prospects in the synthesis of nanomaterials. In this report, a convenient lab-scale continuous stirring tank reactor was assembled and utilized to synthesize Cu7S4 nanocrystals by injecting cupric bromide and sulfur solution in the presence of ascorbic acid and polyethyleneimine at 60 °C. The morphology control of Cu7S4 nanocrystals was accomplished by simply adjusting the agitation speed. Cu7S4 nanofibers with an average diameter of 48 ± 4.42 nm and a length of several micrometers were obtained at 80 rpm. Cu7S4 nanoplates with a thickness of 89 ± 13.56 nm and a plane size of 103 ± 16.47 nm were synthesized at 90 rpm, and the size of the nanoplates was regulated by continuously increasing the agitation speed from 90 rpm to 1000 rpm. Furthermore, the influences of two additional conditions (the mean residence time and the concentration of the feed solution) on the morphology of Cu7S4 nanocrystals, were also investigated. Therefore, these results could facilitate the understanding of the behaviors of CSTR in the synthesis of Cu7S4 nanocrystals and could also provide an important reference for the continuous synthesis of other nanoparticles.

Designing water resistant high entropy oxide materials

The ubiquitous presence of moisture usually shows adverse effects on industrial catalysis. Herein, a concept of engineering entropy to design water-resistant oxide catalysts is proposed. The C3H6 oxidation by spinel ACr2O4 (A=Ni, Mg, Cu, Zn, Co) catalysts is selected as a model. Through DFT calculation, the adsorption energy of C3H6, the dissociation energy of molecular H2O on the oxide surface, and the formation energy of oxygen vacancy all suggest better performance induced by higher configurational entropy. Indeed, (Ni0.2Mg0.2Cu0.2Zn0.2Co0.2)Cr2O4 experimentally show excellent water resistance (>100 h) in C3H6 oxidation, while in sharp contrast binary oxides (e.g., NiCr2O4, CoCr2O4) are deactivated in 20 h. H2O-TPD, in-situ Raman, and in-situ FTIR all confirm the low H2O adsorption energy and strong hydrothermal stability of high entropy oxide, which is attributed to their lower Gibbs free energy. This work may inspire the rational design of water-resistant catalysts.

Mechanistic Insights into Toxicity of Titanium Dioxide Nanoparticles at the Micro- and Macro-levels.

Titanium oxide nanoparticles (TiO2 NPs) have been regarded as a legacy nanomaterial due to their widespread usage across multiple fields. The TiO2 NPs have been and are still extensively used as a food and cosmetic additive and in wastewater and sewage treatment, paints, and industrial catalysis as ultrafine TiO2. Recent developments in nanotechnology have catapulted it into a potent antibacterial and anticancer agent due to its excellent photocatalytic potential that generates substantial amounts of highly reactive oxygen radicals. The method of production, surface modifications, and especially size impact its toxicity in biological systems. The anatase form of TiO2 (<30 nm) has been found to exert better and more potent cytotoxicity in bacteria as well as cancer cells than other forms. However, owing to the very small size, anatase particles are able to penetrate deep tissue easily; hence, they have also been implicated in inflammatory reactions and even as a potent oncogenic substance. Additionally, TiO2 NPs have been investigated to assess their toxicity to large-scale ecosystems owing to their excellent reactive oxygen species (ROS)-generating potential compounded with widespread usage over decades. This review discusses in detail the mechanisms by which TiO2 NPs induce toxic effects on microorganisms, including bacteria and fungi, as well as in cancer cells. It also attempts to shed light on how and why it is so prevalent in our lives and by what mechanisms it could potentially affect the environment on a larger scale.

Preparation Method of a Metal Carrier for a Catalyst for the Recovery of Exhaust Gases from Nitrogen Oxides

The article shows the process of preparing an oxide layer on the surface of titanium for use in industrial catalysis. Data from physical and chemical studies are presented, namely microhardness, porosity, thickness, specific surface area, adhesion and thermal stability of the active layer.To determine the physicochemical characteristics of the resulting oxide layer, the following analysis methods were used: X-ray diffraction analysis (XRD), X-ray diffraction phase analysis (XPA), X-ray absorption analysis (XRA), and X-ray fluorescence analysis. The thickness of the oxide layer depending on the duration of anodization was estimated by optical microscopy.

Synergistic Catalysis of Rh Single‐Atom and Clusters Supported on TiO2 Nanosheet Array for Highly Efficient Removal of CO and NOx

Developing an efficient catalyst is the key to selective catalytic reduction (SCR) of NOx by CO (CO‐SCR) to simultaneously address the pollution of toxic NOx and CO. Herein, a novel Rh/TiO2/Ti monolithic catalyst is designed and synthesized, featuring Rh species in the form of single atoms (Rh1) and clusters (Rhn). This catalyst overcomes the inhibitory effects of oxygen, achieving low‐temperature NO conversion. The investigation substantively contributes insights into the strategic manipulation of active metal components, emphasizing the potential of single‐atom/cluster catalysts to enhance efficiency. The Rh/TiO2/Ti catalyst has demonstrated exceptional catalytic efficacy, achieving 100% NO conversion at a low temperature of 190 °C in the presence of oxygen. Additionally, it exhibits remarkable stability and water resistance for practical applications. Moreover, comprehensive characterization confirms that Rh clusters and single‐atom sites play an important role in the selective adsorption of NO and CO molecules, promoting the formation of –N2O species and ultimately resulting in the complete conversion of NO and CO to N2 and CO2. This study not only provides valuable guidance for designing high‐performance CO‐SCR catalysts but also underscores the potential of single atoms/clusters catalytic systems in both fundamental research and industrial catalysis.

A Transient Iron Carbide Generated by Cyaphide Cleavage.

Despite their potential relevance as molecular models for industrial and biological catalysis, well-defined mononuclear iron carbide complexes are unknown, in part due to the limited number of appropriate C1 synthons. Here, we show the ability of the cyaphide anion (C≡P-) to serve as a C1 source. The high spin (S = 2) cyaphide complex PhB(tBuIm)3Fe-C≡P (PhB(tBuIm)3- = phenyl(tris(3-tert-butylimidazol-2-ylidene)borate) is readily accessed using the new cyaphide transfer reagent [Mg(DippNacNac)(CP)]2 (DippNacNac = CH{C(CH3)N(Dipp)}2 and Dipp = 2,6-di(iso-propyl)phenyl). Phosphorus atom abstraction is effected by the three-coordinate Mo(III) complex Mo(NtBuAr)3 (Ar = 3,5-Me2C6H3), which produces the known phosphide (tBuArN)3Mo≡P along with a transient iron carbide complex PhB(tBuIm)3Fe≡C. Electronic structure calculations reveal that PhB(tBuIm)3Fe≡C adopts a doublet ground state with nonzero spin density on the carbide ligand. While isolation of this complex is thwarted by rapid dimerization to afford the corresponding diiron ethynediyl complex, the carbide can be intercepted by styrene to provide an iron alkylidene.

Light-Driven Reverse Water Gas Shift Reaction with 1000-H Stability on High-Entropy Alloy Catalysts.

Highly stable and active catalysts are of significant importance and a longstanding challenge for a number of industrial chemical transformations. Here, motivated by the principle of the high entropy-stabilized structure, high-entropy alloy-loaded porous TiO2 as an efficient and sintering-resistant catalyst for the light-driven reverse water gas‒shift reaction without external heating is synthesized. The optimized CoNiCuPdRu/TiO2 catalyst exhibits a long-term stability of 1000h (1.23molgmetal -1h-1 CO production rate, >99% high selectivity). In situ characterizations confirm that the slow diffusion effect of high-entropy alloys endows the catalyst with excellent structural stability. The CO adsorption measurements and theoretical calculations consolidate that the hydrogen surface coverage weakens CO adsorption on the catalyst surface. Two major problems of catalyst deactivation - sintering and poisoning, are handled in one case, which synergistically enable unparalleled stability. This work provides new guidance for the rational design of ultradurable harsh-condition operation catalysts for industrial catalysis.

Revolutionizing the Digital Creative Industries: The Role of Artificial Intelligence in Integration, Development, and Innovation

Purpose - Artificial intelligence is profoundly transforming the digital creative industry, becoming a key force in industrial upgrading through technology integration, innovation drive and productivity improvement. Methods- This study uses a variety of methods, including literature review, questionnaire survey, in-depth interview and data analysis, to systematically examine the application effect of AI in the digital creative industry. The structural equation model is used to verify the hypothesized relationship, and the role of AI in promoting industrial integration, development results and innovation catalysis effect are comprehensively analyzed. Research results- The research that AI importantly promotes technological integration, development and innovation inside the digital creative industry, and improves the general overall performance of the industry. The path coefficient is incredibly substantial, and the model fit is good, which verifies the effective position of AI in industrial integration and development. The position of AI not only improves the competitiveness of the industry, but also provides robust support for the personalization and excessive quality of creative products. Originality- This paper demonstrates remarkable originality in theoretical framework construction, empirical data analysis, and exploration of practical challenges and this paper deeply analyzes the multiple mechanisms of AI in the digital creative industry, providing new ideas and specific quantitative evidence for research in related fields. Implications - Practitioners need to actively accept AI era, optimize creative workflows, and enhance production efficiency and constantly enhance their digital talents and cross-area information integration capabilities. Policymakers should formulate focused support policies to promote the vast application and deep integration of AI technologies inside the creative industries.

Synthesis, characterization, and electrochemical uric acid sensing properties of Cu3N nanoparticles

This article explores the development and applications of a Cu3N/GCE-based sensor using differential pulse voltammetry (DPV) for selective uric acid (UA) detection in clinical analysis. The sensor achieves a limit of detection (LOD) of 2.57 × 10−8 M and a quantification limit (QL) of 8.102 × 10−8 M, demonstrating its capability to precisely quantify minute UA concentrations. With rapid responsiveness and reusability over 25 days, it offers cost-effective monitoring of UA levels, even in complex sample matrices. Cu3N also exhibits high efficiency in degrading methylene blue (MB), achieving 87.7% degradation under optimized conditions, suggesting its potential as a photocatalyst for environmental remediation, particularly in dye degradation processes. Overall, Cu3N-based technologies show promise in sensitive UA detection for clinical diagnostics, environmental remediation, and industrial catalysis, highlighting its versatility and broad applicability across scientific and practical domains.

Selective ring-opening in 9,10-dihydrophenanthrene hydrocracking over a practical NiMo/Al2O3-USY catalyst under mild conditions

To understand deeply the cracking pathways of polycyclic aromatic hydrocarbons into monoaromatics, 9,10-dihydrophenanthrene (9,10-DHP) hydrocracking over a real industrial catalyst was investigated systematically at a low temperature and under low pressure in a batch reactor. A new selective ring-opening route of 9,10-DHP hydrocracking by the cleavage of C–C bond in the central saturation ring is found for the first time and confirmed with the intermediate being cracked successively. Three possible pathways of central ring-opening of 9,10-DHP following the protolytic cracking mechanism were suggested by the product distribution. The results indicate that the low density of Brösted acid sites in the zeolites facilitates the selective ring opening of the central ring of the polyaromatics. A comprehensive understanding of the reaction pathways of 9,10-DHP hydrocracking provides a new research approach and beneficial to designing an effective polyaromatic hydrocracking catalyst and corresponding reactor targetting for a high yeild of monoaromatics in practical industrial catalysis.

Continuous‐Flow Solution Plasma for the Atom‐Economic Synthesis of Single/Dual‐Atom Catalysts

AbstractSingle‐atom catalysts (SACs) manifest unique advantages in various aspects of catalysis but face challenges in atom‐economic synthesis. Solution reduction holds the promise of fast, continuous, and low‐cost synthesis of SACs, however, almost no chemical, electrochemical, or photochemical reduction can avoid the aggregation of metal atoms in solution. The issue becomes even tougher to composite dual‐atom metals together. Herein, a continuous‐flow solution plasma (CSP) method is developed, which utilizes high‐flux hydrated electrons, hydrogen radicals, and enhanced metal–support interaction, to achieve over 97% capture efficiency of metal precursors to fabricate CeO2‐based single‐atom Au, Rh, Pd, Ru, and Pt in only 0.03‐s residence time. Further, a programmed CSP synthesis of Au1Rh1/CeO2 and Au1Pd1/CeO2 dual‐atom catalysts is demonstrated. Under Xe lamp irradiation, Au1Rh1/CeO2 breaks room temperature constraints in CO conversion for the water–gas shift reaction with a T50 (the temperature at which 50% CO conversion occurs) of 298 K. The innovative CSP technology provides an atom‐economic approach to the continuous production of SACs using clean electricity without any additional reducing agent, paving the way for the programmed and green synthesis of SACs for industrial catalysis, energy conversion, and environment remedy applications.

Metal-Flavonoid Interactions-From Simple Complexes to Advanced Systems.

For many years, metal-flavonoid complexes have been widely studied as a part of drug discovery programs, but in the last decade their importance in materials science has increased significantly. A deeper understanding of the role of metal ions and flavonoids in constructing simple complexes and more advanced hybrid networks will facilitate the assembly of materials with tailored architecture and functionality. In this Review, we highlight the most essential data on metal-flavonoid systems, presenting a promising alternative in the design of hybrid inorganic-organic materials. We focus mainly on systems containing CuII/I and FeIII/II ions, which are necessary in natural and industrial catalysis. We discuss two kinds of interactions that typically ensure the formation of metal-flavonoid systems, namely coordination and redox reactions. Our intention is to cover the fundamentals of metal-flavonoid systems to show how this knowledge has been already transferred from small molecules to complex materials.

Operando Spectroscopy to Understand Dynamic Structural Changes of Solid Catalysts.

Solid materials like heterogeneous catalysts are highly dynamic and continuously tend to change when exposed to the reaction environment. To understand the catalyst system under true reaction conditions,operando spectroscopy is the key to unravel small changes, which can ultimately lead to a significant difference in catalytic activity and selectivity. This was also the topic of the 7th International Congress on Operando Spectroscopy in Switzerland in 2023. In this article, we discuss various examples to introduce and demonstrate the importance of this area, including examples from emission control for clean air (e.g. CO oxidation), oxidation catalysis in the chemical industry (e.g. oxidation of isobutene), future power-to-X processes (electrocatalysis, CO2 hydrogenation to methanol), and non-oxidative conversion of methane. All of these processes are equally relevant to the chemical industry. Complementary operando techniques such as X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and Raman spectroscopy were utilized to derive the ultimate structure of the catalyst. The variety of conditions requires distinctly different operando cells that can reach a temperature range of 400-1000 °C and pressures up to 40 bar. The best compromise for both the spectroscopy and the catalytic reaction is needed. As an outlook, we highlight emerging methods such as modulation-excitation spectroscopy (MES) or quick-extended X-ray absorption fine structure (QEXAFS) and X-ray photon in/out techniques, which can provide better sensitivity or extend X-ray based operando studies.

Recovering palladium and gold by peroxydisulfate-based advanced oxidation process.

Palladium (Pd) and gold (Au) are the most often used precious metals (PMs) in industrial catalysis and electronics. Green recycling of Pd and Au is crucial and difficult. Here, we report a peroxydisulfate (PDS)-based advanced oxidation process (AOPs) for selectively recovering Pd and Au from spent catalysts. The PDS/NaCl photochemical system achieves complete dissolution of Pd and Au. By introducing Fe(II), the PDS/FeCl2·4H2O solution functioned as Fenton-like system, enhancing the leaching efficiency without xenon (Xe) lamp irradiation. Electron paramagnetic resonance (EPR), 18O isotope tracing experiments, and density functional theory calculations revealed that the reactive oxidation species of SO4·-, ·OH, and Fe(IV)═O were responsible for the oxidative dissolution process. Lixiviant leaching and one-step electrodeposition recovered high-purity Pd and Au. Strong acids, poisonous cyanide, and volatile organic solvents were not used during the whole recovery, which enables an efficient and sustainable precious metal recovery approach and encourage AOP technology for secondary resource recycling.

Promoter Impact on 5Ni/SAPO-5 Catalyst for H2 Production via Methane Partial Oxidation

Compared to steam reforming techniques, partial oxidation of methane (POM) is a promising technology to improve the efficiency of synthesizing syngas, which is a mixture of CO and H2. In this study, partial oxidation of methane (POM) was used to create syngas, a combination of CO and H2, using the SAPO-5-supported Ni catalysts. Using the wetness impregnation process, laboratory-synthesized Ni promoted with Sr, Ce, and Cu was used to modify the SAPO-5 support. The characterization results demonstrated that Ni is appropriate for the POM due to its crystalline structure, improved metal support contact, and increased thermal stability with Sr, Ce, and Cu promoters. During POM at 600 °C, the synthesized 5Ni+1Sr/SAPO-5 catalyst sustained stability for 240 min on stream. While keeping the reactants stoichiometric ratio of (CH4:O2 = 2:1), the addition of Sr promoter and active metal Ni to the SAPO-5 increased the CH4 conversion from 41.13% to 49.11% and improved the H2/CO ratio of 3.33. SAPO-5-supported 5Ni+1Sr catalysts have great potential for industrial catalysis owing to their unique combination of several oxides. This composition not only boosts the catalyst’s activity but also promotes favorable physiochemical properties, resulting in improved production of syngas. Syngas is a valuable intermediate in various industrial processes.

Sustainable synthesis of chromene derivatives catalysed by magnetite nanoparticle cored polyamine dendrimer

Chromene derivatives are naturally occurring heterocyclic compounds used as cosmetic agents, food additives, and potential biodegradable agrochemicals. Normally, its synthesis is carried out with three component/substrates with a suitable base. Dendrimer with amine functionality has several applications in catalysis, more specifically, dendrimers having enriched amino groups with accessible void makes a significant impact in base catalysis. Moreover, polar periphery of the dendrimers may enhance the solubility of material in the reaction medium. Therefore, herein we report the base catalytic efficiency of magnetite nanoparticle supported polyamine dendrimer with enriched amine groups and peripheral carboxyl groups. Actually, magnetite supported polyamine dendrimer synthesis involves the synthesis of PAMAM G3 on magnetite nanoparticle core, followed by reduction of amide group with subsequent functionalization of carboxylic acid terminals. Further, it is used as versatile polyvalent base for the synthesis of chromene derivatives. The magnetite supported dendritic scaffold has accessible voids and polar periphery which enables them dispersible in the reaction medium. The recycle efficiency study confirms, the competency of the material to work in industrial catalysis.

Will Power and Waste-to-X enable the worldwide energy transition to renewables?

AbstractSince the industrial revolution the world economy has grown thanks to energy generated by cheap and abundant fossil resources. Today, due to climate change caused by human-induced CO2 and other greenhouse gas emissions, we are in the midst of a shift away from fossil fuels and towards renewable energy. It remains to be seen how fast this shift will happen and whether the correlating economics are feasible. Increasingly, experts are asking: what role will catalysis play to help drive energy efficiency? With a 60-year history in industrial catalysis, Clariant’s Catalysts business has been a front runner in catalyst and technology development. For more than a decade we have been working in the catalytic Power-to-X segments. This paper presents our understanding on current developments around the important role of Power-to-X and Waste-to-X technologies to enable a worldwide transition of the energy sector to renewables. Graphical abstract

The Industrial Catalysis Section: A Place to Publish Applied Catalysis Research

Chemical technologies provide processes for the large-scale production of materials (i [...]