We report a nanocarbon material with nanodiamond(ND) core and graphene shell(ND@G) as a support for Pd nanocatalysts. The designed catalyst performed good selectivity of styrene(85.2%) at full conversion of phenylacet...We report a nanocarbon material with nanodiamond(ND) core and graphene shell(ND@G) as a support for Pd nanocatalysts. The designed catalyst performed good selectivity of styrene(85.2%) at full conversion of phenylacetylene and superior stability under mild conditions. Supported Pd catalysts are characterized by means of high resolution transmission electron microscopy(HRTEM), Raman, X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS) and H2 temperature-programmed reduction(H2-TPR).The results clearly show that formation of the strong metal-support interaction(SMSI) between Pd nanoclusters and the defective graphene shell helpfully modifies the selectivity and stability of the Pd-based catalysts.展开更多
Based on the outstanding application advantages of nitrogen-rich materials with regular porous frameworks in the capture of gaseous radioactive iodine,a series of covalent organic frameworks(COFs)with dual channels an...Based on the outstanding application advantages of nitrogen-rich materials with regular porous frameworks in the capture of gaseous radioactive iodine,a series of covalent organic frameworks(COFs)with dual channels and abundant tertiary-amine active sites were constructed herein via a unique multinitrogen node design.The high density of up-to-six nitrogen adsorption sites in a single structural unit of the products effectively improved the adsorption capacities of the materials for iodine.Moreover,the adsorption affinity of the active sites can be further regulated by charge-induced effect of different electrondonating groups introduced into the COFs.Adsorption experiments combined with DFT theoretical calculations confirmed that the introduction of electron-donating groups can effectively increase the electron density around the active sites and enhance the binding energy between the materials and iodine,and thus improve the iodine adsorption capacity to 5.54 g/g.The construction strategy of multi-nitrogen node and charge-induced effect proposed in this study provides an important guidance for the study of the structure-activity relationship of functional materials and the design and preparation of high-performance iodine adsorption materials.展开更多
The pursuit of energy conservation and environmental protection has always been a hot topic in the catalytic fields,which is inseparable from the rational designing of efficient catalysts and an in-depth understanding...The pursuit of energy conservation and environmental protection has always been a hot topic in the catalytic fields,which is inseparable from the rational designing of efficient catalysts and an in-depth understanding of the catalytic reaction mechanism.In this work,fully-exposed Pt clusters were fabricated on the atomically dispersed Sn decorated nanodiamond/graphene(Sn-ND@G)hybrid support and employed for direct dehydrogenation(DDH)of ethylbenzene(EB)to styrene(ST).The detailed structural characterizations revealed the fully-exposed Pt clusters were stabilized on Sn-ND@G,assisted by the spatial separation of atomically dispersed Sn species.The as-prepared Pt/Sn-ND@G catalyst showed enhanced ST yield(136.2 molEB·molpt-1·h-1 EB conversion rate and 99.7%ST selectivity)and robust long-term stability at 500℃for the EB DDH reaction,compared with the traditional ND@G supported Pt nanoparticle catalyst(Pt/ND@G).The ST prefers to desorb from the fully-exposed Pt clusters,resulting in the enhanced DDH catalytic performance of the Pt/Sn-ND@G catalyst.The present work paves a new way for designing highly dispersed and stable supported metal catalysts for DDH reactions.展开更多
基金supported by the Ministry of Science and Technology (2016YFA0204100)the National Natural Science Foundation of China (21573254, 21703261 and 91545110)+2 种基金the Youth Innovation Promotion Association (CAS), and the Sinopec China and Strategic Priority Research Program of the Chinese Academy of Sciences (XDA09030103)the Chongqing Research Program of Basic Research and Frontier Technology (cstc2016jcyjA0432)Scientific and Technological Research Program of Chongqing Municipal Education Commission (KJ1600328)
文摘We report a nanocarbon material with nanodiamond(ND) core and graphene shell(ND@G) as a support for Pd nanocatalysts. The designed catalyst performed good selectivity of styrene(85.2%) at full conversion of phenylacetylene and superior stability under mild conditions. Supported Pd catalysts are characterized by means of high resolution transmission electron microscopy(HRTEM), Raman, X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS) and H2 temperature-programmed reduction(H2-TPR).The results clearly show that formation of the strong metal-support interaction(SMSI) between Pd nanoclusters and the defective graphene shell helpfully modifies the selectivity and stability of the Pd-based catalysts.
基金supported by the National Natural Science Foundation of China(No.21976125)the Sichuan Science and Technology Program(Nos.2020JDRC0014 and 2021YFG0229)+1 种基金the support from the Fundamental Research Funds for the Central Universitiesthe Comprehensive Training Platform Specialized Laboratory,College of chemistry,Sichuan University。
文摘Based on the outstanding application advantages of nitrogen-rich materials with regular porous frameworks in the capture of gaseous radioactive iodine,a series of covalent organic frameworks(COFs)with dual channels and abundant tertiary-amine active sites were constructed herein via a unique multinitrogen node design.The high density of up-to-six nitrogen adsorption sites in a single structural unit of the products effectively improved the adsorption capacities of the materials for iodine.Moreover,the adsorption affinity of the active sites can be further regulated by charge-induced effect of different electrondonating groups introduced into the COFs.Adsorption experiments combined with DFT theoretical calculations confirmed that the introduction of electron-donating groups can effectively increase the electron density around the active sites and enhance the binding energy between the materials and iodine,and thus improve the iodine adsorption capacity to 5.54 g/g.The construction strategy of multi-nitrogen node and charge-induced effect proposed in this study provides an important guidance for the study of the structure-activity relationship of functional materials and the design and preparation of high-performance iodine adsorption materials.
基金supported by the National Key Research and Development Program of China(No.2021YFA1502802)the National Natural Science Foundation of China(Nos.21961160722,92145301,U21B2092,22072162,and 91845201)+5 种基金the Liaoning Revitalization Talents Program(No.XLYC1907055)Natural Science Foundation of Liaoning Province(No.2021-MS001)IMR Innovation Fund(No.2022-PY05)Dalian National Lab for Clean Energy(No.DNL Cooperation Fund 202001)the Sinopec China.N.W.hereby acknowledges the funding support from the Research Grants Council of Hong Kong(Nos.C6021-14E,N_HKUST624/19,and 16306818)The XAS experiments were conducted in Shanghai Synchrotron Radiation Facility(SSRF)。
文摘The pursuit of energy conservation and environmental protection has always been a hot topic in the catalytic fields,which is inseparable from the rational designing of efficient catalysts and an in-depth understanding of the catalytic reaction mechanism.In this work,fully-exposed Pt clusters were fabricated on the atomically dispersed Sn decorated nanodiamond/graphene(Sn-ND@G)hybrid support and employed for direct dehydrogenation(DDH)of ethylbenzene(EB)to styrene(ST).The detailed structural characterizations revealed the fully-exposed Pt clusters were stabilized on Sn-ND@G,assisted by the spatial separation of atomically dispersed Sn species.The as-prepared Pt/Sn-ND@G catalyst showed enhanced ST yield(136.2 molEB·molpt-1·h-1 EB conversion rate and 99.7%ST selectivity)and robust long-term stability at 500℃for the EB DDH reaction,compared with the traditional ND@G supported Pt nanoparticle catalyst(Pt/ND@G).The ST prefers to desorb from the fully-exposed Pt clusters,resulting in the enhanced DDH catalytic performance of the Pt/Sn-ND@G catalyst.The present work paves a new way for designing highly dispersed and stable supported metal catalysts for DDH reactions.