Synergy of heterogeneous Co/Ni dual atoms enabling selective C-O bond scission of lignin coupling with in-situ N-functionalization

Selective cleavage of Csp^(2)-OCH_(3)bond in lignin without breaking other types of C-O bonds followed by N-functionalization is fascinating for on-purpose valorization of biomass.Here,a Co/Ni-based dual-atom catalyst CoNiDA@NC prepared by in-situ evaporation and acid-etching of metal species from tailor-made metal–organic frameworks was efficient for reductive upgrading of various lignin-derived phenols to cyclohexanols(88.5%–99.9%yields),which had ca.4 times higher reaction rate than the single-atom catalyst and was superior to state-of-the-art heterogeneous catalysts.The synergistic catalysis of Co/Ni dual atoms facilitated both hydrogen dissociation and hydrogenolysis steps,and could optimize adsorption configuration of lignin-derived methoxylated phenols to further favor the Csp^(2)-OCH_(3)cleavage,as elaborated by theoretical calculations.Notably,the CoNi_(DA)@NC catalyst was highly recyclable,and exhibited excellent demethoxylation performance(77.1%yield)in real lignin monomer mixtures.Via in-situ cascade conversion processes assisted by dual-atom catalysis,various high-value N-containing chemicals,including caprolactams and cyclohexylamines,could be produced from lignin.

Toward Next-Generation Heterogeneous Catalysts:Empowering Surface Reactivity Prediction with Machine Learning

Heterogeneous catalysis remains at the core of various bulk chemical manufacturing and energy conversion processes,and its revolution necessitates the hunt for new materials with ideal catalytic activities and economic feasibility.Computational high-throughput screening presents a viable solution to this challenge,as machine learning(ML)has demonstrated its great potential in accelerating such processes by providing satisfactory estimations of surface reactivity with relatively low-cost information.This review focuses on recent progress in applying ML in adsorption energy prediction,which predominantly quantifies the catalytic potential of a solid catalyst.ML models that leverage inputs from different categories and exhibit various levels of complexity are classified and discussed.At the end of the review,an outlook on the current challenges and future opportunities of ML-assisted catalyst screening is supplied.We believe that this review summarizes major achievements in accelerating catalyst discovery through ML and can inspire researchers to further devise novel strategies to accelerate materials design and,ultimately,reshape the chemical industry and energy landscape.

Single-atom catalysis: Bridging the homo-and heterogeneous catalysis

Single-atom catalysis,the catalysis by single-atom catalysts(SACs),has attracted considerable attention in recent years as a new frontier in the heterogeneous catalysis field.SACs have the advantages of both homogeneous catalysts(isolated active sites)and heterogeneous catalysts(stable and easy to separate),and are thus predicted to be able to bridge the homo-and heterogeneous catalysis.This prediction was first experimentally demonstrated in 2016.In this mini-review,we summarize the few homogeneous catalysis progresses reported recently where SACs have exhibited promising application:a)Rh/ZnO and Rh/CoO SAC have been used successfully in hydroformylation of olefin of which the activity are comparable to the homogeneous Wilkinson’s catalyst;b)a Pt/Al2O3 SAC has shown excellent performance in hydrosilylation reaction;and c)M-N-C SACs(M=Fe,Co etc.)have been applied in the activation of C–H bonds.All of these examples suggest that fabrication of suitable SACs could provide a new avenue for the heterogenization of homogeneous catalysts.These pioneering works shed new light on the recognition of single-atom catalysis in bridging the homo-and heterogeneous catalysis.

Importance, features and uses of metal oxide catalysts in heterogeneous catalysis

This short review paper aims at assembling the present state of the art of the multiuses of metal oxides in heterogeneous catalysis, concerning liquid and gaseous phases of the reactant mixtures on solid catalysts. It includes the description of the main types of metal oxide catalysts, of their various preparation procedures and of the main reactions catalysed by them (acid-base type, selective and total oxidations, bi-functional catalysis, photocatalysis, biomass treatments, environmental catalysis and some of the numerous industrial applications). Challenges and prospectives are also discussed.

Progress on Porous Ceramic Membrane Reactors for Heterogeneous Catalysis over Ultrafine and Nano-sized Catalysts

Heterogeneous catalysts with ultrafine or nano particle size have currently attracted considerable attentions in the chemical and petrochemical production processes, but their large-scale applications remain challenging because of difficulties associated with their efficient separation from the reaction slurry. A porous ceramic membrane reactor has emerged as a promising method to solve the problem concerning catalysts separation in situ from the reaction mixture and make the production process continuous in heterogeneous catalysis. This article presents a review of the present progress on porous ceramic membrane reactors for heterogeneous catalysis, which covers classification of configurations of porous ceramic membrane reactor, major considerations and some important industrial applications. A special emphasis is paid to major considerations in term of application-oriented ceramic membrane design, optimization of ceramic membrane reactor performance and membrane fouling mechanism. Finally, brief concluding remarks on porous ceramic membrane reactors are given and possible future research interests are also outlined.

Heterogeneous catalysis under flow for the 21st century fine chemical industry

Due to metal leaching and poor catalyst stability, the chemical industry's fine chemical and pharmaceutical sectors have been historically reluctant to use supported transition metal catalysts to manufacture fine chemicals and active pharmaceutical ingredients. With the advent of new generation supported metal catalysts and flow chemistry, we argue in this study, this situation is poised to quickly change. Alongside heterogenized metal nanoparticles, both single-site molecular and single-atom catalyst will become ubiquitous. This study offers a critical outlook taking into account both technical and economic aspects.

Recent progress on synthesis of ZIF-67-based materials and their application to heterogeneous catalysis

In recent years,an increasing amount of interest has been dedicated to the synthesis and application of ZIF-67-based materials due to their exceptionally high surface area,tunable porosity,and excellent thermal and chemical stabilities.This review summarizes the latest strategies of synthesizing ZIF-67-based materials by exploring the prominent examples.Then,the recent progress in the applications of ZIF-67-based materials in heterogeneous catalysis,including catalysis of the redox reactions,addition reactions,esterification reactions,Knoevenagel condensations,and hydrogenation-dehydrogenation reactions,has been elaborately discussed.Finally,we end this work by shedding some light on the large-scale industrial production of ZIF-67-based materials and their applications in the future.

Direct carbon dioxide hydrogenation to produce bulk chemicals and liquid fuels via heterogeneous catalysis

The hydrogenation of carbon dioxide(CO_(2))to produce chemicals and transportation liquid fuels in huge demand via heterogeneous thermochemical catalysis achieved using renewable energy has received increasing attention,and substantial advances have been made in this research field in recent years.In this study,we summarize our progress in the rational design and construction of highly efficient catalysts for CO_(2) hydrogenation to methanol,lower olefins,aromatics,and gasolineand jet fuel-range hydrocarbons.The structure‐performance relationship,nature of the active sites,and mechanism of the reactions occurring over these catalysts are explored by combining computational and experimental evidence.The results of this study will promote further fundamental studies and industrial applications of heterogeneous catalysts for CO_(2) hydrogenation to produce bulk chemicals and liquid fuels.

Chlorobenzene degradation by electro-heterogeneous catalysis in aqueous solution:intermediates and reaction mechanism

This study was performed to investigate the variables that influence chlorobenzene (CB) degradation in aqueous solution by electro-heterogeneous catalysis.The effects of current density,pH,and electrolyte concentration on CB degradation were determined.The degradation effciency of CB was almost 100% with an initial CB concentration of 50 mg/L,current density 15 mA/cm2,initial pH 10,electrolyte concentration 0.1 mol/L,and temperature 25°C after 90 min of reaction.Under the same conditions,the degradation eff...

Synthesis,Crystal Structure and Heterogeneous Catalysis of a New Chiral Manganese Coordination Polymer Based on the Schiff-base Ligand

A homochrial manganese（Ⅲ） complex（1） derived from chiral salen ligand（1 R,2 R）-（-）-1,2-diphenylethane-1,2-diamine-N,N？-bicarboxyl-salicylidene） has been synthesized through solvothermal procedure and characterized by IR,elemental analysis,TGA,circular dichroism（CD）,powder and single-crystal X-ray crystallography.It crystallizes in orthorhombic,space group P212121 with a = 9.108（3）,b = 16.431（5）,c = 26.531（6） A,V = 3970.4（19） A^3,Z = 4,Dc = 1.248 g/cm^3,F（000） = 1568,Mr = 745.73,μ = 0.383 mm^-1,the final GOOF = 0.957,R = 0.0631 and wR = 0.1079 for 13250 observed reflections with I 〉 2σ（I）.The coordination polymer 1 possesses a 1 D infinite zigzag chain architecture constructed by the dicarboxyl-functionalized metallosalen ligand（Mn-salen）,and the polymeric chains are further assembled into a 3D supramolecular network structure via strong intermolecular hydrogen bonding interactions between adjacent zigzag chains.As a heterogeneous catalyst,1 was used as an efficient heterogeneous catalyst for the asymmetric olefin epoxidation.

Study on the Mechanism of Heterogeneous Catalysis (4)—Electron Cyclic Donate-Accept Catalysis Mechanism-ECDAM or Electron Orbital Deformation-Reversion Cyclic Catalysis Mechanism-EODRM

This paper has expounded the derivation of the Electron Cyclic Donate-Accept Catalysis Mechanism-ECDAM or Electron Orbital Deformation-Reversion Cyclic Catalysis Mechanism-EODRM and its three main arguments as well as three argument verifications. These three main arguments are: 1) There is a demarcation between catalysts and poisons, or promoters and poisons. 2) The relative activities of catalysts or poisons of poisons are closely related to the Electrical Negativity Values-ENV of catalysts or poison. 3) The activities or ENVs of catalysts are closely related to the chemical states of substance being added. The ECDAM or EODRM can also be extended to iron or metal base catalyst for selecting promoter, support and judging poison. It can also be extended to the study of the fire retardant of carbon materials. The author holds that the catalytic phenomenon should be physical phenomenon rather than chemical phenomenon or not completely chemical phenomenon at least.

Study on the Mechanism of Heterogeneous Catalysis (1) —The Measurement of Equilibrium Pressure of Reaction BaCO₃+ C = BaO + 2CO, the Chemical States of Fe in Reaction Tank, and Chemical Reaction Model Catalytic Cycle Mechanism (CRMM)

The results on the equilibrium pressure measurement of BaCO3 + C = BaO + 2CO reaction and the demonstration of chemical state of iron proved that decomposition-generation cycle of BaCO3 and oxidation-reduction cycle of Fe in that reaction condition case were impossible to occur. The Chemical Reaction Model Catalytic Cycle Mechanism-CRMM does not exist at all for BaCO3, Fe, Noble metal catalysts. To call CRMM as a “principle” was obviously inappropriate. The TOF (Turnover Frequency—TOF: unit: s-1) was used to measure the activity size and life of catalyst, and it is clearly out of nothing.

TWO-STEP MECHANISM IN HETEROGENEOUS CATALYSIS AND DYNAMIC ANALYSIS

Recent development of the dynamic analysis technique has made it possible to measure separately kinetic parameters of a catalytic reaction as well as to study the effect of catalyst preparation parameters. But its application is still limned to first-order reaction. This work is aimed to demonstrate in some detail that,by comparison of the reaction rate expressions with the two-step mechanism used in catalytic kinetics and dynamic analysis, these methods can be extended to non-first-order reaction, and the kinetic parameters measured by dynamic techniques are interpreted for different reaction mechanisms.

Availability of elements for heterogeneous catalysis: Predicting the industrial viability of novel catalysts

Growing concern regarding the sustainability of the chemical industry has driven the developmentof more efficient catalytic reactions.First‐generation estimates of catalyst viability are based oncrustal abundance,which has severe limitations.Herein,we propose a second‐generation approachto predicting the viability of novel catalysts prior to industrial implementation to benefit the globalchemical industry.Using this prediction,we found that a correlation exists between catalyst consumptionand the annual production or price of the catalyst element for11representative industrialcatalytic processes.Based on this correlation,we have introduced two new descriptors for catalystviability,namely,catalyst consumption to availability ratio per annum(CCA)and consumed catalystcost to product value ratio per annum(CCP).Based on evaluations of CCA and CCP for selected industrial reactions,we have grouped catalysts from the case studies according to viability,allowing the identification of general limits of viability based on CCA and CCP.Calculating the CCA and CCP and their comparing with the general limits of viability provides researchers with a novel framework for evaluating whether the cost or physical availability of a new catalyst could be limiting.We have extended this analysis to calculate the predicted limits of economically viable production and product cost for new catalysts.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Practical C–P bond formation via heterogeneous photoredox and nickel synergetic catalysis

An efficient C–P bond formation reaction was developed by virtue of the synergetic catalysis strategy by merging heterogeneous photocatalysis and nickel catalysis.This platform utilizing cadmium sulfide semiconductors as heterogeneous photocatalysts and nickel complexes as transition metal catalysts provided a variety of organophosphorus compounds from readily available aryl and vinyl halides,as well as aryl triflates,with generally a good-to-excellent reaction efficiency(31 examples,46%-98%yields).The current protocol features mild reaction conditions,a broad substrate scope,recyclability of photocatalysts,and inexpensive catalysts,thus defining the practical and economic proprieties of the present catalyst system.

Study on the Mechanism of Heterogeneous Catalysis (2) <br>—The Relative Catalytic Activities of Fe, Co, Ni, Cu, Ag and SiO2 in the Carbon Catalyzed Gasification Reaction

This is a validation article. The experimental results such as the relative catalytic activities of Fe, Co, Ni, Cu, Ag and SiO2 poisoning in the carbothermic reduction iron oxide show that the Electron Cyclic Donate-Accept Catalytic Mechanism-ECDAM or Electron Obital Deformation-Recovery cycle Catalysis Mechanism-EODRM are credible, and the Chemical Reaction Model Catalytic Cyclic Mechanism-CRMM such as the Oxygen Transfer Mechanism-OTT that is long and wide spread in the literature is completely unreliable. Because the Fe, Co, Ni, Cu, Ag were unlikely to react cyclic oxidation—reduction reaction with the carbon in the carbon reduction reaction tank.

Study on the Mechanism of Heterogeneous Catalysis (3) —The Catalysis of W, Mo, S and SiO₂on Carbon Dissolving and Mechanism of Carbon Dissolving in the Iron-Graphite Compact

This is an article that validates Electron Cyclic Donate-Accept Catalysis Mechanism-ECDAM or Electron Orbital Deformation-Recovery Cycle Catalysis Mechanism-EODRM. In this paper, the influence of compact density, sintering temperature and time, vacuum degree, atmosphere and alloying element on the carbon dissolving rate into γ-Fe were studied. The experiment results have been reported. The way that the carbon is dissolved into γ-Fe was discussed. Gas phase composition and temperature play an important role on the carbon dissolving rate. The carbon gasification reaction is the determining step of dissolving carbon process. K2CO3, W and Mo are a catalysts, and their active size are K2CO3 > W > Mo. S and SiO2 are a poison, and their poison size are SiO2 > S. The experiment results are completely consistent with the original judgment of ECDAM.

Recent Advances in Multifunctional Capsule Catalysts in Heterogeneous Catalysis

Capsule catalysts composed of pre-shaped core catalysts and layer zeolites have been widely used in the tandem reactions where multiple continuous reactions are combined into one process. They show excellent catalytic performance in heterogeneous catalysis, including the direct synthesis of middle isoparaflins or dimethyl ether from syngas, as compared to the conventional hybrid catalysts. The present review highlights the recent development in the design of capsule catalysts and their catalytic applications in heterogeneous catalysis. The capsule catalyst preparation methods are introduced in detail, such as hydrothermal synthe- sis method, dual-layer method, physically adhesive method and single crystal crystallization method. Purthermore, several new applications of capsule catalysts in heterogeneous cat- alytic processes are presented such as in the direct synthesis of liquefied petroleum gas from syngas, the direct synthesis of para-xylene from syngas and methane dehydroaromatization. In addition, the development in the design of multifunctional capsule catalysts is discussed, which makes the capsule catalyst not just a simple combination of two dill）rent catalysts, but has some special functions such as changing the surface hydrophobic or acid properties of the core catalysts. Finally, the future perspectives of the design and applications of capsule catalysts in heterogeneous catalysis are provided.

A Comparison of Two Heterogeneous Catalysis Mechanisms

In this paper, two heterogeneous catalysis mechanisms are introduced, namely: Chemical Reaction Mode Cyclic Catalysis Mechanism—CRMM and Electron Orbital Deformation-Recovery Cyclic Catalysis Mechanism—EODRM (or Electron Cyclic Donate-Adopt catalysis Mechanism—ECDAM. A number of difficulties encountered by CRMM are listed. The author clearly points out that CRMM is not credible. This false theory has misled us for more than 100 years. About EODRM or ECDAM, the article also gives a brief description. The key point of EODRM or ECDAM is that catalysts do not participate in chemical reactions, and catalysis phenomena are physical rather than chemical phenomena. It’s completely different from CRMM. The theory contains three main points: 1) There is a demarcation between the catalyst and the poison;2) The active size of the catalyst or the poison size of the poison is closely related to the electronegative size of the catalyst or poison;3) The active size of catalyst is closely related to the chemical state. The selectivity of catalyst is related to energy level. Photocatalysis, electrocatalysis, laser catalysis and microwave catalysis are all physical phenomena. It has different energy levels. According to this theory, the author thinks that there are several problems worth studying in production and scientific research, such as: alumina in the Fe ammonia synthesis catalyst has a serious poison effect on the iron catalyst, resulting in three high situations in ammonia synthesis production (high temperature, high pressure, high energy consumption). The support materials of automotive exhaust purification catalyst have used Cordierite (2MgO-2Al2O3-5SiO2) ceramic honeycomb support, which has a serious poisoning effect on noble metal catalysts, a lot of noble metals are wasted, and so on. These problems have long been ignored by the catalytic academia;the author considers that this reason may be due to a misunderstanding or mistranslation on the term “catalysis” and “catalyst”.