Mesoporous Ni-Al composite oxide(MNA)with excellent textural and surface properties was prepared using a facile calcination-induced metal heteroatom doping approach and was evaluated as support of Pt-based catalyst fo...Mesoporous Ni-Al composite oxide(MNA)with excellent textural and surface properties was prepared using a facile calcination-induced metal heteroatom doping approach and was evaluated as support of Pt-based catalyst for methylcyclohexane dehydrogenation at a low temperature.The homogeneous incorporation of Ni atoms into the mesoporous framework of alumina and the formation of surface Ni-O-Al bonds benefit the generation of surface coordinated unsaturated aluminum species,which play a crucial role in highly homogenously dispersing Pt active sites in a form of single-atom clusters.Consequently,the resultant catalyst Pt/MNA displayed significantly improved catalytic performance.For example,at 300℃,catalyst Pt/MNA demonstrated a notable catalytic activity with a maximum hydrogen evolution rate of 3057 mmol/gPt/min,even after a long-time reaction up to 100 h or regeneration,which is inspiringly superior to the state-of-the-art supported Ptbased catalysts.The obviously boosted catalytic reactivity of catalyst Pt/MNA can be attributed to the excellent structural and textural properties,the remarkably raised Pt utilization efficiency,and the synergic catalytic effect derived from the interface electron transfer from support MNA to metallic Pt active sites.Our results provided a rational design strategy for the development of promising Pt-based catalyst for methylcyclohexane dehydrogenation,which is vital in the utilization of methylcyclohexane-toluene system for hydrogen storage.展开更多
Mesoporous CeO2-MnOx binary oxides with different Mn/Ce molar ratios were prepared by hydrothermal synthesis and characterized by scanning electron microscopy （SEM）, N2 sorption, X-ray diffraction （XRD）, X-ray pho...Mesoporous CeO2-MnOx binary oxides with different Mn/Ce molar ratios were prepared by hydrothermal synthesis and characterized by scanning electron microscopy （SEM）, N2 sorption, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and H2 temperature-programmed reduction （H2-TPR）. The characterization results indicated that the CeO2-MnOx catalysts exhibited flower-like microspheres with high specific surface areas, and partial Mn cations could be incorporated into CeO2 lattice to form solid solution. The CeO2-MnOx catalysts showed better catalytic activity for CO oxidation than that prepared by the coprecipitation method. Furthermore, the CeO2-MnOx catalyst with Mn/Ce molar ratio of 1 in the synthesis gel （Ce-Mn-1） exhibited the best catalytic activity, over which the conversion of CO could achieve 90% at 135 ℃. This was ascribed to presence of more Mn species with higher oxida- tion state on the surface and the better reducibility over the Ce-Mn-I catalyst than other CeO2-MnOx catalysts.展开更多
A mesoporous Al-Mg composite oxide with a hexagonal structure was synthesized with aluminium nitrate and magnesium nitrate as the reagents and sodium dodecyl sulfate（SDS） as the template in the presence of ethylened...A mesoporous Al-Mg composite oxide with a hexagonal structure was synthesized with aluminium nitrate and magnesium nitrate as the reagents and sodium dodecyl sulfate（SDS） as the template in the presence of ethylenediamine. The XRD, nitrogen adsorption-desorption and TEM studies indicate that the composite has a hexagonal framework structure and an average pore diameter of 2. 6 nm. The TG/DTA spectra indicate that the decomposition and the removal of the occluded surfactant of the sample take place in a range of 230-550 ℃. The mesoporous Al-Mg composite oxide exhibites a highly catalytic activity for the oxyethylation of fatty alcohols. Narrow-range distributed ethoxylates are formed in the presence of the mesoporous Al-Mg composite oxide catalyst. The distribution selectivity coefficient（Cx） is 24 when the mesoporous Al-Mg composite oxide was used as a catalyst for the oxyethylation of octanol and the average adduct degree of ethoxylates is 6. 4.展开更多
基金supported by the National Natural Science Foundation of China(21975174 and 22378286)the Natural Science Foundation of Shanxi Province,China(202403021221036)+1 种基金the Funds for Central Government to Guide Local Science and Technology Development(YDZJSX2021A014)the Research Project Supported by Shanxi Scholarship Council of China(2024-036).
文摘Mesoporous Ni-Al composite oxide(MNA)with excellent textural and surface properties was prepared using a facile calcination-induced metal heteroatom doping approach and was evaluated as support of Pt-based catalyst for methylcyclohexane dehydrogenation at a low temperature.The homogeneous incorporation of Ni atoms into the mesoporous framework of alumina and the formation of surface Ni-O-Al bonds benefit the generation of surface coordinated unsaturated aluminum species,which play a crucial role in highly homogenously dispersing Pt active sites in a form of single-atom clusters.Consequently,the resultant catalyst Pt/MNA displayed significantly improved catalytic performance.For example,at 300℃,catalyst Pt/MNA demonstrated a notable catalytic activity with a maximum hydrogen evolution rate of 3057 mmol/gPt/min,even after a long-time reaction up to 100 h or regeneration,which is inspiringly superior to the state-of-the-art supported Ptbased catalysts.The obviously boosted catalytic reactivity of catalyst Pt/MNA can be attributed to the excellent structural and textural properties,the remarkably raised Pt utilization efficiency,and the synergic catalytic effect derived from the interface electron transfer from support MNA to metallic Pt active sites.Our results provided a rational design strategy for the development of promising Pt-based catalyst for methylcyclohexane dehydrogenation,which is vital in the utilization of methylcyclohexane-toluene system for hydrogen storage.
基金supported by National Basic Research Program of China(2010CB732300,2013CB933201)National High Technology Research and Development Program of China(2011AA03A406,2012AA062703)+2 种基金the National Natural Science Foundation of China(21103048,21273150)Shu Guang Project of Shanghai Municipal Education CommissionShanghai Education Development Foundation(10SG30)
文摘Mesoporous CeO2-MnOx binary oxides with different Mn/Ce molar ratios were prepared by hydrothermal synthesis and characterized by scanning electron microscopy （SEM）, N2 sorption, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and H2 temperature-programmed reduction （H2-TPR）. The characterization results indicated that the CeO2-MnOx catalysts exhibited flower-like microspheres with high specific surface areas, and partial Mn cations could be incorporated into CeO2 lattice to form solid solution. The CeO2-MnOx catalysts showed better catalytic activity for CO oxidation than that prepared by the coprecipitation method. Furthermore, the CeO2-MnOx catalyst with Mn/Ce molar ratio of 1 in the synthesis gel （Ce-Mn-1） exhibited the best catalytic activity, over which the conversion of CO could achieve 90% at 135 ℃. This was ascribed to presence of more Mn species with higher oxida- tion state on the surface and the better reducibility over the Ce-Mn-I catalyst than other CeO2-MnOx catalysts.
基金Supported by the Natural Science Foundation of Heilongjiang Province(No.9810B).
文摘A mesoporous Al-Mg composite oxide with a hexagonal structure was synthesized with aluminium nitrate and magnesium nitrate as the reagents and sodium dodecyl sulfate（SDS） as the template in the presence of ethylenediamine. The XRD, nitrogen adsorption-desorption and TEM studies indicate that the composite has a hexagonal framework structure and an average pore diameter of 2. 6 nm. The TG/DTA spectra indicate that the decomposition and the removal of the occluded surfactant of the sample take place in a range of 230-550 ℃. The mesoporous Al-Mg composite oxide exhibites a highly catalytic activity for the oxyethylation of fatty alcohols. Narrow-range distributed ethoxylates are formed in the presence of the mesoporous Al-Mg composite oxide catalyst. The distribution selectivity coefficient（Cx） is 24 when the mesoporous Al-Mg composite oxide was used as a catalyst for the oxyethylation of octanol and the average adduct degree of ethoxylates is 6. 4.
