Pub Date : 2019-02-12DOI: 10.1039/9781788016971-00166
I. Ogino
Metal–support interface often plays dominant roles in supported catalysts. When supported metals are extremely small and consist of single or a few atoms, the effects of metal–support interface are maximized. In such atomically dispersed supported metal catalysts, supports act as ligands and influence the metal–adsorbate and metal–metal interactions significantly. As a result, the structure of supported metal species varies dynamically in response to changes in reaction conditions. Because supported metal species are extremely small, often non-uniform in structure and their structures change dynamically, it is challenging to elucidate the structure–performance relationships of such catalysts. However, efforts to improve precise synthesis methods, atomistic characterization techniques, and theoretical calculations have provided crucial fundamental insights into the structure of active sites, roles of ligands, and effects of neighboring metal atoms. This chapter shows some of the research works aimed to deepen fundamental understanding of the structure–performance relationships of atomically dispersed supported metal catalysts. In addition, to illustrate the importance of such catalysts and prospective opportunities for new catalytic technology that are potentially enabled by them, some recent research works are described.
{"title":"Understanding atomically dispersed supported metal catalysts: structure and performance of active sites","authors":"I. Ogino","doi":"10.1039/9781788016971-00166","DOIUrl":"https://doi.org/10.1039/9781788016971-00166","url":null,"abstract":"Metal–support interface often plays dominant roles in supported catalysts. When supported metals are extremely small and consist of single or a few atoms, the effects of metal–support interface are maximized. In such atomically dispersed supported metal catalysts, supports act as ligands and influence the metal–adsorbate and metal–metal interactions significantly. As a result, the structure of supported metal species varies dynamically in response to changes in reaction conditions. Because supported metal species are extremely small, often non-uniform in structure and their structures change dynamically, it is challenging to elucidate the structure–performance relationships of such catalysts. However, efforts to improve precise synthesis methods, atomistic characterization techniques, and theoretical calculations have provided crucial fundamental insights into the structure of active sites, roles of ligands, and effects of neighboring metal atoms. This chapter shows some of the research works aimed to deepen fundamental understanding of the structure–performance relationships of atomically dispersed supported metal catalysts. In addition, to illustrate the importance of such catalysts and prospective opportunities for new catalytic technology that are potentially enabled by them, some recent research works are described.","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86241927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-12DOI: 10.1039/9781788016971-00242
Kazumasa Murata, K. Ueda, Yuji Mahara, Junya Ohyama, A. Satsuma
In situ and operando analyses are the methods to observe the real features of catalysts under the reaction conditions. These methods can clarify the dynamics of active species of catalysts and reaction scheme on catalyst surface through transient response method, kinetic study, temperature dependence of catalysts and products, and so on. In this review, progress in in situ and operando analyses is summarized with emphasis on environmental catalysts, i.e., catalysts for combustion, selective reduction of NO, automotive three-way catalysis, and related materials.
{"title":"In situ and operando analysis of environmental catalysts – studies on reaction mechanism and active site","authors":"Kazumasa Murata, K. Ueda, Yuji Mahara, Junya Ohyama, A. Satsuma","doi":"10.1039/9781788016971-00242","DOIUrl":"https://doi.org/10.1039/9781788016971-00242","url":null,"abstract":"In situ and operando analyses are the methods to observe the real features of catalysts under the reaction conditions. These methods can clarify the dynamics of active species of catalysts and reaction scheme on catalyst surface through transient response method, kinetic study, temperature dependence of catalysts and products, and so on. In this review, progress in in situ and operando analyses is summarized with emphasis on environmental catalysts, i.e., catalysts for combustion, selective reduction of NO, automotive three-way catalysis, and related materials.","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86469726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-12DOI: 10.1039/9781788016971-00297
E. Wolf, Anand Kumar, A. Mukasyan
In this chapter, we summarize work accomplished primarily by the authors on the use of solution combustion synthesis (SCS) in catalysis. Research in combustion synthesis at University of Notre Dame started with the group of Prof. A. Varma, now at Purdue University, in collaboration with Prof. A. Mukasyan and its application to catalysis was pursued jointly with Prof. E. Wolf. Prof. A. Kumar worked on the subject during his graduate studies at Notre Dame and now he is continuing work on the application of combustion synthesis to catalysis at Qatar University. After an introduction to combustion synthesis, we describe reaction pathways involved in the preparation of unsupported and supported catalysts using SCS. The catalytic applications focus on preparation and performance of active and stable catalysts for the hydrogen generation from methanol and ethanol, followed by application to electrocatalysis for fuels cell utilization.
{"title":"Combustion synthesis: a novel method of catalyst preparation","authors":"E. Wolf, Anand Kumar, A. Mukasyan","doi":"10.1039/9781788016971-00297","DOIUrl":"https://doi.org/10.1039/9781788016971-00297","url":null,"abstract":"In this chapter, we summarize work accomplished primarily by the authors on the use of solution combustion synthesis (SCS) in catalysis. Research in combustion synthesis at University of Notre Dame started with the group of Prof. A. Varma, now at Purdue University, in collaboration with Prof. A. Mukasyan and its application to catalysis was pursued jointly with Prof. E. Wolf. Prof. A. Kumar worked on the subject during his graduate studies at Notre Dame and now he is continuing work on the application of combustion synthesis to catalysis at Qatar University. After an introduction to combustion synthesis, we describe reaction pathways involved in the preparation of unsupported and supported catalysts using SCS. The catalytic applications focus on preparation and performance of active and stable catalysts for the hydrogen generation from methanol and ethanol, followed by application to electrocatalysis for fuels cell utilization.","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89154712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-02DOI: 10.1080/2055074X.2019.1595872
S. Siwal, N. Devi, Venkata K. Perla, Sarit K. Ghosh, K. Mallick
ABSTRACT Polymeric form of graphitic carbon nitride (CN) has attracted much attention in recent years because of their performance as a support material of various reactions. Here, we report the fabrication of CN and gold nanoparticle-decorated CN system for electrochemical methanol oxidation process. The microscopic, optical, thermal, and surface properties of the synthesized materials have been analyzed using different characterization techniques. Both the synthesized materials were successfully used as electrocatalyst for methanol oxidation reaction under the alkaline media. The stability and the tolerance of the synthesized catalysts have been studied, in connection with the title reaction, on the basis of oxophilicity of the gold. The strong coordination between gold nanoparticles and amine groups of CN facilitates the electron transfer from amine to metal, which makes the gold particles more electron rich and consequently makes the Au-CN system more active for electrocatalytic methanol oxidation reaction. Graphical abstract
{"title":"Promotional role of gold in electrochemical methanol oxidation","authors":"S. Siwal, N. Devi, Venkata K. Perla, Sarit K. Ghosh, K. Mallick","doi":"10.1080/2055074X.2019.1595872","DOIUrl":"https://doi.org/10.1080/2055074X.2019.1595872","url":null,"abstract":"ABSTRACT Polymeric form of graphitic carbon nitride (CN) has attracted much attention in recent years because of their performance as a support material of various reactions. Here, we report the fabrication of CN and gold nanoparticle-decorated CN system for electrochemical methanol oxidation process. The microscopic, optical, thermal, and surface properties of the synthesized materials have been analyzed using different characterization techniques. Both the synthesized materials were successfully used as electrocatalyst for methanol oxidation reaction under the alkaline media. The stability and the tolerance of the synthesized catalysts have been studied, in connection with the title reaction, on the basis of oxophilicity of the gold. The strong coordination between gold nanoparticles and amine groups of CN facilitates the electron transfer from amine to metal, which makes the gold particles more electron rich and consequently makes the Au-CN system more active for electrocatalytic methanol oxidation reaction. Graphical abstract","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/2055074X.2019.1595872","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44043229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.1039/9781788016971-00037
Songbo He
Catalytic wet oxidation (CWO) is regarded as the second generation wastewater treatment technology and is specialized in the degradation or mineralization of the highly concentrated, toxic, refractory, and non-biodegradable industrial wastewater. Since the first industrial installation of CWO in the 1950s, many commercial CWO processes have been developed and applied for different wastewater sources and applications. This Chapter addresses the homogeneous CWO processes (Loprox, Ciba-Geigy, IT EnviroScience, ATHOS and ORCAN) and heterogeneous CWO processes (Osaka Gas, Nippon Shokubai, Kurita, CALIPHOX, DICP and Watercatox), and also the development on the homogeneous catalysts (cations and anions) and heterogeneous catalysts (supported noble metal catalysts and non-noble metal oxides). The application perspective of the CWO, such as for the treatment of the wastewater from the biomass pyrolysis for bio-based fuels and chemicals process, is also discussed.
{"title":"Catalytic wet oxidation: process and catalyst development and the application perspective","authors":"Songbo He","doi":"10.1039/9781788016971-00037","DOIUrl":"https://doi.org/10.1039/9781788016971-00037","url":null,"abstract":"Catalytic wet oxidation (CWO) is regarded as the second generation wastewater treatment technology and is specialized in the degradation or mineralization of the highly concentrated, toxic, refractory, and non-biodegradable industrial wastewater. Since the first industrial installation of CWO in the 1950s, many commercial CWO processes have been developed and applied for different wastewater sources and applications. This Chapter addresses the homogeneous CWO processes (Loprox, Ciba-Geigy, IT EnviroScience, ATHOS and ORCAN) and heterogeneous CWO processes (Osaka Gas, Nippon Shokubai, Kurita, CALIPHOX, DICP and Watercatox), and also the development on the homogeneous catalysts (cations and anions) and heterogeneous catalysts (supported noble metal catalysts and non-noble metal oxides). The application perspective of the CWO, such as for the treatment of the wastewater from the biomass pyrolysis for bio-based fuels and chemicals process, is also discussed.","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82900982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-10-02DOI: 10.1080/2055074X.2018.1565002
Tao Li, Minkyu Kim, Zhu Liang, A. Asthagiri, J. Weaver
ABSTRACT We investigated the adsorption and oxidation of H2 on O-rich IrO2(110) using temperature programmed reaction spectroscopy (TPRS) and density functional theory (DFT) calculations. Our results show that H2 dissociation occurs efficiently on O-rich IrO2(110) at low temperature and initiates from an adsorbed H2 σ-complex on the coordinatively-unsaturated Ir atoms (Ircus). We find that on-top oxygen atoms (Oot), adsorbed on the Ircus sites, promote the desorption-limited evolution of H2O during subsequent oxidation of the adsorbed hydrogen on IrO2(110) while suppressing reaction-limited production of H2O via the recombination of bridging HO groups (HObr) (~500 to 750 K) during TPRS. The desorption-limited TPRS peak of H2O shifts from ~490 to 550 K with increasing Oot coverage, demonstrating that Oot atoms stabilize adsorbed OH and H2O species. DFT predicts that molecularly-adsorbed H2 dissociates on O-rich IrO2(110) at low temperature and that the resulting H-atoms redistribute to produce a mixture of HObr and HOot groups, with equilibrium favouring HOot groups. Our calculations further predict that subsequent H2O evolution occurs through the recombination of HObr/HOot and HOot/HOot pairs, and that these reactions represent desorption-limited pathways because the dissociative chemisorption of H2O is favoured over molecular adsorption on IrO2(110). The higher stability of HOot groups and their preferred formation causes the higher-barrier HOot/HOot recombination reaction to become the dominant pathway for H2O formation with increasing Oot coverage, consistent with the experimentally-observed upshift in the H2O TPRS peak temperature. Graphical abstract
{"title":"Hydrogen oxidation on oxygen-rich IrO2(110)","authors":"Tao Li, Minkyu Kim, Zhu Liang, A. Asthagiri, J. Weaver","doi":"10.1080/2055074X.2018.1565002","DOIUrl":"https://doi.org/10.1080/2055074X.2018.1565002","url":null,"abstract":"ABSTRACT We investigated the adsorption and oxidation of H2 on O-rich IrO2(110) using temperature programmed reaction spectroscopy (TPRS) and density functional theory (DFT) calculations. Our results show that H2 dissociation occurs efficiently on O-rich IrO2(110) at low temperature and initiates from an adsorbed H2 σ-complex on the coordinatively-unsaturated Ir atoms (Ircus). We find that on-top oxygen atoms (Oot), adsorbed on the Ircus sites, promote the desorption-limited evolution of H2O during subsequent oxidation of the adsorbed hydrogen on IrO2(110) while suppressing reaction-limited production of H2O via the recombination of bridging HO groups (HObr) (~500 to 750 K) during TPRS. The desorption-limited TPRS peak of H2O shifts from ~490 to 550 K with increasing Oot coverage, demonstrating that Oot atoms stabilize adsorbed OH and H2O species. DFT predicts that molecularly-adsorbed H2 dissociates on O-rich IrO2(110) at low temperature and that the resulting H-atoms redistribute to produce a mixture of HObr and HOot groups, with equilibrium favouring HOot groups. Our calculations further predict that subsequent H2O evolution occurs through the recombination of HObr/HOot and HOot/HOot pairs, and that these reactions represent desorption-limited pathways because the dissociative chemisorption of H2O is favoured over molecular adsorption on IrO2(110). The higher stability of HOot groups and their preferred formation causes the higher-barrier HOot/HOot recombination reaction to become the dominant pathway for H2O formation with increasing Oot coverage, consistent with the experimentally-observed upshift in the H2O TPRS peak temperature. Graphical abstract","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/2055074X.2018.1565002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47498530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-07-03DOI: 10.1080/2055074X.2018.1496611
Xing Guo, A. Alemozafar, R. Madix
ABSTRACT There is long-term interest in catalyst poisoning due to the buildup of carbonaceous species on catalytic metal surfaces. These species are often derived from the reactants themselves in reactions parallel to the primary catalytic cycle. Generally, these species are believed to be randomly distributed on the surface, with locally high concentrations. Using scanning tunneling microscopy (STM), we have found that upon annealing to 400 K a stable intermediate formed by partial oxidation of toluene on Ag(110) forms highly ordered domains with a length scale well over 1000 Å, limited only by the size of surface terraces. Temperature-programmed reaction spectroscopy and STM suggest the intermediate to be adsorbed benzoate species, C6H5CHOO, which decomposes to carbon dioxide and benzene near 550 K when heated. Graphical Abstract
{"title":"Long-range ordering of stable, surface-bound intermediates: RAIRS, TPRS and STM studies of toluene oxidation on Ag(110)","authors":"Xing Guo, A. Alemozafar, R. Madix","doi":"10.1080/2055074X.2018.1496611","DOIUrl":"https://doi.org/10.1080/2055074X.2018.1496611","url":null,"abstract":"ABSTRACT There is long-term interest in catalyst poisoning due to the buildup of carbonaceous species on catalytic metal surfaces. These species are often derived from the reactants themselves in reactions parallel to the primary catalytic cycle. Generally, these species are believed to be randomly distributed on the surface, with locally high concentrations. Using scanning tunneling microscopy (STM), we have found that upon annealing to 400 K a stable intermediate formed by partial oxidation of toluene on Ag(110) forms highly ordered domains with a length scale well over 1000 Å, limited only by the size of surface terraces. Temperature-programmed reaction spectroscopy and STM suggest the intermediate to be adsorbed benzoate species, C6H5CHOO, which decomposes to carbon dioxide and benzene near 550 K when heated. Graphical Abstract","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/2055074X.2018.1496611","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42419535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-04-03DOI: 10.1080/2055074X.2018.1477315
P. Ellis, Christopher M Brown, P. Bishop, D. Ievlev, Jinlong Yin, K. Cooke, R. Palmer
ABSTRACT The selective hydrogenation of alkynes is an important reaction in the synthesis of fine and bulk chemicals. We show that the synthesis of metal nanoparticles in the gas phase, followed by deposition onto conventional support powders results in materials that perform as well as those made by typical methods for making catalysts (impregnation, deposition). The nature of the active sites in these catalysts is explored. Graphical Abstract
{"title":"High-selectivity palladium catalysts for the partial hydrogenation of alkynes by gas-phase cluster deposition onto oxide powders","authors":"P. Ellis, Christopher M Brown, P. Bishop, D. Ievlev, Jinlong Yin, K. Cooke, R. Palmer","doi":"10.1080/2055074X.2018.1477315","DOIUrl":"https://doi.org/10.1080/2055074X.2018.1477315","url":null,"abstract":"ABSTRACT The selective hydrogenation of alkynes is an important reaction in the synthesis of fine and bulk chemicals. We show that the synthesis of metal nanoparticles in the gas phase, followed by deposition onto conventional support powders results in materials that perform as well as those made by typical methods for making catalysts (impregnation, deposition). The nature of the active sites in these catalysts is explored. Graphical Abstract","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/2055074X.2018.1477315","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43557077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-01-02DOI: 10.1080/2055074X.2018.1434986
B. Caglar, A. C. Kizilkaya, J. Niemantsverdriet, C. J. Weststrate
Abstract The present article aims to show how work function measurements (WF) can be applied in the study of elementary surface reaction steps on metallic single crystal surfaces. The work function itself can in many cases not be interpreted directly, as it lacks direct information on structural and chemical nature of the surface and adsorbates, but it can be a powerful tool when used together with other surface science techniques which provide information on the chemical nature of the adsorbed species. We here, illustrate the usefulness of work function measurements using Rh(100) as our model catalyst. The examples presented include work function measurements during adsorption, surface reaction, and desorption of a variety of molecules relevant for heterogeneous catalysis. Surface coverage of adsorbates, isosteric heat of adsorption, and kinetic parameters for desorption, desorption/decomposition temperatures of surface species, different reaction regimes were determined by WF with the aid of other surface science techniques.
{"title":"Application of work function measurements in the study of surface catalyzed reactions on Rh(1 0 0)","authors":"B. Caglar, A. C. Kizilkaya, J. Niemantsverdriet, C. J. Weststrate","doi":"10.1080/2055074X.2018.1434986","DOIUrl":"https://doi.org/10.1080/2055074X.2018.1434986","url":null,"abstract":"Abstract The present article aims to show how work function measurements (WF) can be applied in the study of elementary surface reaction steps on metallic single crystal surfaces. The work function itself can in many cases not be interpreted directly, as it lacks direct information on structural and chemical nature of the surface and adsorbates, but it can be a powerful tool when used together with other surface science techniques which provide information on the chemical nature of the adsorbed species. We here, illustrate the usefulness of work function measurements using Rh(100) as our model catalyst. The examples presented include work function measurements during adsorption, surface reaction, and desorption of a variety of molecules relevant for heterogeneous catalysis. Surface coverage of adsorbates, isosteric heat of adsorption, and kinetic parameters for desorption, desorption/decomposition temperatures of surface species, different reaction regimes were determined by WF with the aid of other surface science techniques.","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/2055074X.2018.1434986","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46000248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-01-02DOI: 10.1080/2055074X.2018.1433598
Daniel R. Jones, Sarwat Iqbal, L. Thomas, S. Ishikawa, Christian Reece, Peter J. Miedziak, D. Morgan, J. Bartley, D. Willock, W. Ueda, G. Hutchings
Abstract We have investigated xNi–yCu–ZrO2 catalysts for the selective synthesis of γ-valerolactone from levulinic acid (LA). A series of xNi–yCu–ZrO2 catalysts with a consistent metal loading of 50% but varying Ni and Cu composition were prepared by an oxalate gel precipitation method and tested for LA hydrogenation. Ni-rich catalysts showed higher catalytic activity compared with Cu-rich formulations with a 45Ni–5Cu–ZrO2 composition yielding 76% γ-valerolactone after a reaction time of 30 min at 200 °C. Characterisation of the materials by XRD, surface area measurements and TPR allow us to attribute the differences in performance seen for different compositions to particle size and nanoparticle dispersion effects. DFT calculations also showed that a shift of d-band centre to higher energies with the mole fraction of Ni in Cu–Ni alloys would be expected to lead to improved hydrogen dissociation in Ni-rich catalysts and so aid hydrogenation activity.
{"title":"xNi–yCu–ZrO2 catalysts for the hydrogenation of levulinic acid to gamma valorlactone","authors":"Daniel R. Jones, Sarwat Iqbal, L. Thomas, S. Ishikawa, Christian Reece, Peter J. Miedziak, D. Morgan, J. Bartley, D. Willock, W. Ueda, G. Hutchings","doi":"10.1080/2055074X.2018.1433598","DOIUrl":"https://doi.org/10.1080/2055074X.2018.1433598","url":null,"abstract":"Abstract We have investigated xNi–yCu–ZrO2 catalysts for the selective synthesis of γ-valerolactone from levulinic acid (LA). A series of xNi–yCu–ZrO2 catalysts with a consistent metal loading of 50% but varying Ni and Cu composition were prepared by an oxalate gel precipitation method and tested for LA hydrogenation. Ni-rich catalysts showed higher catalytic activity compared with Cu-rich formulations with a 45Ni–5Cu–ZrO2 composition yielding 76% γ-valerolactone after a reaction time of 30 min at 200 °C. Characterisation of the materials by XRD, surface area measurements and TPR allow us to attribute the differences in performance seen for different compositions to particle size and nanoparticle dispersion effects. DFT calculations also showed that a shift of d-band centre to higher energies with the mole fraction of Ni in Cu–Ni alloys would be expected to lead to improved hydrogen dissociation in Ni-rich catalysts and so aid hydrogenation activity.","PeriodicalId":43717,"journal":{"name":"Catalysis Structure & Reactivity","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/2055074X.2018.1433598","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46703476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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