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Clarification of copper species over Cu-SAPO-34 catalyst by DRIFTS and DFT study of CO adsorption

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Science China Chemistry 2017年第7期60卷 912-919页

作者： Zheng Qu Ying Li shouying huang Pengzhen Chen Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Center of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

In this work, the nature, location and evolution of Cu+ ions in Cu-SAPO-34 are investigated by diffuse reflectance infrared Fourier transform spectrum(DRIFTS) of CO adsorption and density functional theory(DFT) calculation. By combination with DFT results, characteristic Cu+–CO bands located at 2154 and 2136 cm.1 are attributed to CO adsorbed on Cu+ ions located at sites I(in the plane of six-membered ring connected to the large cages) and site II(in the eight-membered ring cages near the tilted four membered ring) in the framework of H-SAPO-34 zeolite. Subsequently, both the influences of Cu loading and preparation method are considered and discussed. By varying the Cu loading, the site-occupation preference of Cu+ ions on site I is confirmed,especially at low Cu loadings. Through elevating the desorption temperature, migration of Cu+ ions is revealed because of the adsorption-induced effect. Furthermore, a facile and more efficient approach to introduce Cu+ ions into CHA zeolite, compared with solid-state ion exchange with CuCl and conventional ion exchange in aqueous solution, and the different preparation methods also result in different occupations of Cu+ ions.

关键词： Cu-SAPO-34 CO adsorption DRIFTS DFT

Immobilization of carbonic anhydrase for facilitated CO2 capture and separation

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Chinese Journal of Chemical Engineering 2020年第11期28卷 2817-2831页

作者： Zhenhua Wu Yan Nan Yang Zhao Xueying Wang shouying huang Jiafu Shi Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering&TechnologyTianjin UniversityTianjin 300072China School of Environmental Science&Engineering Tianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering Tianjin 300072China

Carbonic anhydrase(CA)as a typical metalloenzyme in biological system can accelerate the hydration/dehydration of carbon dioxide(CO2,the major components of greenhouse gases),which performer with high selectivity,environmental friendliness and superior ***,the free form of CA is quite expensive(~RMB 3000/100 mg),unstable,and non-reusable as the free form of CA is not easy for recovery from the reaction environment,which severely limits its large-scale industrial *** immobilization may solve these problems at the same *** this context,many efforts have been devoted to improving the chemical and thermal stabilities of CA through immobilization *** recently,a wide range of available inorganic,organic and hybrid compounds have been explored as carrier materials for CA immobilization,which could not only improve the tolerance of CA in hazardous environments,but also improve the efficiency and recovery to reduce the cost of large-scale application of *** excellent reviews about immobilization methods and application potential of CA have been *** contrast,in our review,we stressed on the way to better retain the biocatalytic activity of immobilized CA system based on different carrier materials and to solve the problems facing in practical operations *** concluding remarks are presented with a perspective on constructing efficient CO2 conversion systems through rational combining CA and advanced carrier materials.

关键词： Carbon dioxide Carbonic anhydrase Enzyme immobilization Capture and separation Carrier materials

Enhanced CuCl dispersion by regulating acidity of MCM-41 for catalytic oxycarbonylation of ethanol to diethyl carbonate

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Frontiers of Chemical Science and Engineering 2015年第2期9卷 224-231页

作者： Pengzhen CHEN shouying huang Jijie ZHANG Shengping WANG Xinbin MA Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Center of Chemical Science and Engineering School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

CuCl supported on molecular sieves has attracted increasing attention in catalyzing oxidative carbonylation of ethanol to diethyl carbonate. Mesoporous MCM-41 has been widely used as catalyst support due to its large surface area and well defined mesoporous structure. Considering its intrinsic weak acidity, MCM- 41 was modified by a simple impregnation method to incorporate A1. The incorporation of A1 components resulted in the high dispersion of Cu species and the increase of acid sites without changing the mesoporous structure of MCM-41, and thus enhanceed the catalytic activity of CuCl/MCM-41 for diethyl carbonate synthesis.

关键词： MCM-41 acidity oxidative carbonylation,diethyl carbonate

Importance of metal location in M-H zeolite for synergistically catalyzing dimethyl ether carbonylation

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Chinese Journal of Chemical Engineering 2022年第1期35卷 350-357页

作者： Shiyue Li shouying huang Kai Cai Ying Li Jing Lv Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Center of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China

Mordenite(MOR)has shown great potential to catalyze dimethyl ether(DME)carbonylation to methyl acetate(MA)in *** synergy between metal species and Brønsted acid sites accelerates DME *** we designed and prepared two catalysts with different Ag locations by seed-directed growth method and two-step impregnation method(named as Ag@HMOR and Ag/HMOR-out,respectively),to explain the effect of Ag location on catalytic *** results of TEM,XPS,CO-IR and UV–Vis showed that Ag species mainly presented as Ag^(0) species over both Ag@HMOR and Ag/***,Ag^(0) species mainly located in the micropores of Ag@HMOR,while as for Ag/HMOR-out,Ag^(0) mainly existed on external *** comparing the performance of the catalysts with different Ag positions,we confirmed that the Ag^(0) species encapsulated in the channels of HMOR promoted the DME carbonylation,which revealed the importance of spatial adjacency on the acid-metal catalysts.

关键词： Dimethyl ether Carbonylation Silver modification Metal location

A density functional theory study on the mechanism of dimethyl ether carbonylation over heteropolyacids catalyst

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Frontiers of Chemical Science and Engineering 2021年第2期15卷 319-329页

作者： Kai Cai Ying Li Hongbao Shen Zaizhe Cheng shouying huang Yue Wang Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Center of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China

Dimethyl ether(DME)carbonylation is considered as a key step for a promising route to produce ethanol from ***(HPAs)are proved to be efficient catalysts for DME *** this work,the reaction mechanism of DME carbonylation was studied theoretically by using density functional theory calculations on two typical HPA models(HPW,HSiW).The whole process consists of three stages:DME dissociative adsorption,insertion of CO into methoxyl group and formation of product methyl *** activation barriers of all possible elementary steps,especially two possible paths for CO insertion were calculated to obtain the most favorable reaction mechanism and rate-limiting ***,the effect of the acid strength of Brønsted acid sites on reactivity was studied by comparing the activation barriers over HPW and HSiW with different acid strength,which was determined by calculating the deprotonation energy,Mulliken population analyses and adsorption energies of pyridine.

关键词： dimethyl ether carbonylation mechanism heteropolyacids density functional theory

Oxycarbonylation of methanol over modified CuY: Enhanced activity by improving accessibility of active sites

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Chinese Chemical Letters 2019年第3期30卷 775-778页

作者： Hexin Zhou Shengping Wang Baowei Wang Xinbin Ma shouying huang Key Laboratory for Green Chemical Technology School of Chemical Engineering and Technology Tianjin University Collaborative Innovation Center of Chemical Science and Engineering

CuY zeolite is a promising catalyst in the field of manufacturing dimethyl carbonate(DMC) through oxidative carbonylation of methanol. Cu^+ exchanged with Br?nsted acid sites are supposed to be active for this reaction. However, the location of Cu^+ in small cages can not interact with reactants because of steric hindrance, which lead to a waste of Cu species. In this work, NH_4F solution was used to modify the pore structure of zeolite Y by etching the framework T atoms. Physical and chemical adsorption of probe molecules with different size are used to determine the changes of porosity as well as the accessibility of Cu^+ sites. At an optimized etching time, the small cages were opened with maintained zeolitic framework. As a result, more Cu^+ species located in small cages become accessible to reactants, which contributes to the enhanced activity in this reaction.

关键词： Carbonylation of methanol Post-treatment Accessibility Zeolite Y NH4F solution etching

Enhancing the CO_(2) methanation activity of Ni/CeO_(2) via activation treatment-determined metal-support interaction

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Journal of Energy Chemistry 2021年第8期30卷 334-342,I0008页

作者： Shuangxi Lin Ziwen Hao Jindong Shen Xiao Chang shouying huang Maoshuai Li Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Center of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin University300350 TianjinChina

The metal-support interaction is of critical importance to enhance the catalytic activity and ***,it is still challenging to construct an appropriate interaction starting from the catalyst fabrication and/or *** herein established low-temperature treatment of Ni^(2+)ions impregnated on ceria in reductive atmosphere and reduction-oxidation cycles as effective approachs to regulate the metal-support interaction and raise the catalytic performance in the CO_(2)*** proposed construction approach yielded Ni/Ce O_(2)that displayed highly dispersed Ni nanoparticles in contact with Ce O_(2)(111)and(100)facet,higher density of surface oxygen vacancies and larger amounts of weak basic sites relative to the reference samples,which increased the capacity for H2 and CO_(2)adsorption/*** interaction resulted in appreciably(2-3 fold)higher activity in the CO_(2)methanation with maintaining almost full selectivity to CH4 and high *** of Ni surface by Ce O_(2)-x thin layer as a typical structure of strong metal-support interaction resulting from high-temperature reduction,can be alleviated via reduction-oxidation *** also demonstrate the activation treatment-determined metalsupport interaction effect can generally extend to(Ti O_(2)and Zr O_(2))supported Ni catalysts.

关键词： CO_(2)methanation Nickel Ceria Metal-support interaction Thermal treatment Reduction-oxidation cycles

Enhanced hydrodeoxygenation of lignin-derived anisole to arenes catalyzed by Mn-doped Cu/Al_(2)O_(3)

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Green Energy & Environment 2023年第3期8卷 927-937页

作者： Xiaofei Wang Shixiang Feng Yue Wang Yujun Zhao shouying huang Shengping Wang Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Centre of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhou350207China

Lignin is a renewable carbon resource to produce arenes due to its abundant aromatic *** the liquid-phase hydrodeoxygenation(HDO)based on metallic catalysts,the preservation of aromatic rings in lignin or its derivatives remains a ***,we synthesized Mndoped Cu/Al_(2)O_(3) catalysts from layered double hydroxides(LDHs)for liquid-phase HDO of lignin-derived *** doping significantly enhanced the selective deoxygenation of anisole to arenes and inhibited the saturated hydrogenation on Cu/Al_(2)O_(3).With Mn doping increasing,the surface of Cu particles was modified with MnO_(x) along with enhanced generation of oxygen vacancies(Ov).The evolution of active sites structure led to a controllable adsorption geometry of anisole,which was beneficial for increasing arenes *** a result,the arenes selectivity obtained on 4Cu/8Mn4AlO_(x) was increased to be more than 6 folds of that value on 4Cu/4Al_(2)O_(3) over the synergistic sites between metal Cu and Ov generated on MnO_(x).

关键词： Anisole Hydrodeoxygenation Oxygen vacancy Arenes Metal oxide

Size dependence of carbon-encapsulated iron-based nanocatalysts for Fischer–Trposch synthesis

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Nano Research 2023年第5期16卷 6270-6277页

作者： Xiaoxue Han Jing Lv shouying huang Qiao Zhao Yue Wang Zhenhua Li Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Zhejiang Institute of Tianjin University Ningbo 315201China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

The conversion from syngas derived from non-petroleum recourses to liquid fuels and chemicals via Fischer–Tropsch synthesis(FTS)is regarded as an alternative and potential *** catalyst with controllable particle size and clarifying size effect are of significance to promote the ***,we engineered carbon-encapsulation structure to restrict particle growth but avoid strong metal–support *** prepared carbon-encapsulated nanoparticles(Fe@C)showed a superior catalytic activity compared with conventional carbon-supported nanoparticles(Fe/C).By tuning particle size from 3.0 to 9.1 nm,a volcano-like trend of iron time yield(FTY)peaked at 2659μmol·gFe^(−1)·s^(−1)is obtained with an optimum particle size of 5.3 *** to temperature-programmed reduction and desorption results,a linear relationship between apparent turnover frequency and CO dissociation capacity was *** enhanced CO dissociative adsorption along with weakened H_(2)activation on larger nanoparticles resulted in higher C_(5+)*** study provides a strategy to synthesize carbon supported metal catalysts with controllable particle size and insight into size effect on Fe-based catalytic FTS.

关键词： Fischer–Tropsch synthesis iron-based catalyst carbon-encapsulation size effect