The crystal size distribution（CSD）was determined with small angle X-ray scattering technique.Theanticoking property of Ni-catalysts was investigated with the steam reforming of n-heptane in a TG-monitoredflow reacto...The crystal size distribution（CSD）was determined with small angle X-ray scattering technique.Theanticoking property of Ni-catalysts was investigated with the steam reforming of n-heptane in a TG-monitoredflow reactor.The results of this study show that the rate of coking on the supported Ni-catalysts depends main-ly on the percentage content of the large size fraction（25-70nm）of Ni-crystallites,and that the dispersion ofNi-crystallites and the anticoking property of the Ni/α-Al<sub>2</sub>O<sub>3</sub> catalysts were promoted obviously by theLa<sub>2</sub>O<sub>3</sub>-modification method.The variation of the Ni-CSD and the anticoking property of the catalysts were fur-ther tested through different periods of hydrothermal treatment.It is found that the content of the largeNi-crystal size fraction and the coking rate pass correspondingly through a maximum.展开更多
Ni-based catalysts hold great potential in the light-driven dry reforming of methane(DRM)for syngas production due to their low cost and comparable catalytic performance to conventional noble-metal catalysts.However,t...Ni-based catalysts hold great potential in the light-driven dry reforming of methane(DRM)for syngas production due to their low cost and comparable catalytic performance to conventional noble-metal catalysts.However,the currently available Ni-based catalysts are confronted with low light-driven DRM efficiency and poor stability attributed to the coking.Herein,an atomically dispersed Ni-loaded CeO_(2)(Ni/CeO_(2))for light-drivenDRMis prepared by employing a polyol-mediated doping method to allow the high loading concentration of Ni on the CeO_(2),which overcomes the conventional atomically dispersed metal problem of low loading content.The atomically dispersed nature of the Ni can induce enormous CH4 activation sites for the reaction and photothermal effects for driving the reaction,while the CeO_(2) can facilitateCO_(2) activation.Therefore,the optimized atomically dispersed Ni-loaded CeO_(2) demonstrates an excellent light-drivenDRMperformance forH_(2)(626.5 mmol gcat^(-1) h^(-1))and CO(728.5 mmol gcat^(-1) h^(-1))production.More importantly,the optimized sample sustains its DRM performance after 100 h of continuous test,and such excellent stability of the presence of enormous Ni–O pairs can prevent the rapid conversion of CH_(x) intermediates into coke.This work demonstrates the meticulous design of non-noble metal catalysts for the lightdriven DRM with both high performance and stability.展开更多
文摘The crystal size distribution（CSD）was determined with small angle X-ray scattering technique.Theanticoking property of Ni-catalysts was investigated with the steam reforming of n-heptane in a TG-monitoredflow reactor.The results of this study show that the rate of coking on the supported Ni-catalysts depends main-ly on the percentage content of the large size fraction（25-70nm）of Ni-crystallites,and that the dispersion ofNi-crystallites and the anticoking property of the Ni/α-Al<sub>2</sub>O<sub>3</sub> catalysts were promoted obviously by theLa<sub>2</sub>O<sub>3</sub>-modification method.The variation of the Ni-CSD and the anticoking property of the catalysts were fur-ther tested through different periods of hydrothermal treatment.It is found that the content of the largeNi-crystal size fraction and the coking rate pass correspondingly through a maximum.
基金financial support from the National Key R&D Program of China(2022YFE0126500)the National Natural Science Foundation of China(52261135635.52372165,U23A2091,22150610467)+1 种基金the Natural Science Foundation of Anhui Province(2308085MB32)the Scientific and Technological Research Council of Turkey(TUBITAK,122N434).
文摘Ni-based catalysts hold great potential in the light-driven dry reforming of methane(DRM)for syngas production due to their low cost and comparable catalytic performance to conventional noble-metal catalysts.However,the currently available Ni-based catalysts are confronted with low light-driven DRM efficiency and poor stability attributed to the coking.Herein,an atomically dispersed Ni-loaded CeO_(2)(Ni/CeO_(2))for light-drivenDRMis prepared by employing a polyol-mediated doping method to allow the high loading concentration of Ni on the CeO_(2),which overcomes the conventional atomically dispersed metal problem of low loading content.The atomically dispersed nature of the Ni can induce enormous CH4 activation sites for the reaction and photothermal effects for driving the reaction,while the CeO_(2) can facilitateCO_(2) activation.Therefore,the optimized atomically dispersed Ni-loaded CeO_(2) demonstrates an excellent light-drivenDRMperformance forH_(2)(626.5 mmol gcat^(-1) h^(-1))and CO(728.5 mmol gcat^(-1) h^(-1))production.More importantly,the optimized sample sustains its DRM performance after 100 h of continuous test,and such excellent stability of the presence of enormous Ni–O pairs can prevent the rapid conversion of CH_(x) intermediates into coke.This work demonstrates the meticulous design of non-noble metal catalysts for the lightdriven DRM with both high performance and stability.
