Carbon dioxide and methane are two main greenhouse gases which are contributed to serious global warming.Fortunately,dry reforming of methane(DRM),a very important reaction developed decades ago,can convert these two ...Carbon dioxide and methane are two main greenhouse gases which are contributed to serious global warming.Fortunately,dry reforming of methane(DRM),a very important reaction developed decades ago,can convert these two major greenhouse gases into value-added syngas or hydrogen.The main problem retarding its industrialization is the seriously coking formation upon the nickel-based catalysts.Herein,a series of confined indium-nickel(In-Ni)intermetallic alloy nanocatalysts(In_(x)Ni@SiO_(2))have been prepared and displayed superior coking resistance for DRM reaction.The sample containing 0.5 wt.%of In loading(In_(0.5)Ni@SiO_(2))shows the best balance of carbon deposition resistance and DRM reactivity even after 430 h long term stability test.The boosted carbon resistance can be ascribed to the confinement of core–shell structure and to the transfer of electrons from Indium to Nickel in In-Ni intermetallic alloys due to the smaller electronegativity of In.Both the silica shell and the increase of electron cloud density on metallic Ni can weaken the ability of Ni to activate C–H bond and decrease the deep cracking process of methane.The reaction over the confined InNi intermetallic alloy nanocatalyst was conformed to the Langmuir-Hinshelwood(L-H)mechanism revealed by in situ diffuse reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS).This work provides a guidance to design high performance coking resistance catalysts for methane dry reforming to efficiently utilize these two main greenhouse gases.展开更多
Photothermal catalytic CO_(2)hydrogenation is an effective means of utilizing carbon resources. However, it is severely limited in terms of kinetics and thermodynamics. Therefore, it is necessary to meticulously desig...Photothermal catalytic CO_(2)hydrogenation is an effective means of utilizing carbon resources. However, it is severely limited in terms of kinetics and thermodynamics. Therefore, it is necessary to meticulously design catalysts to solve this problem. Herein, a sandwich structured Ni O@In Ni/In_(2)O_(3)is designed to intrinsically regulate the direction of photogenerated carriers transfer,resulting in a CO yield of 42.97 mmol g^(-1)h^(-1)(1290.3 μmol h^(-1)) with a selectivity near to 100%. In Ni alloy favors the collection of photogenerated carriers by the parallel way and enhancement of the adsorption and activation of CO_(2)molecules. NiO grown on the surface of In Ni alloy not only improves the adsorption of H_(2)and provides sufficient H^(+)for the reaction, but also makes In Ni alloy more stable during the reaction process. The photothermal effect caused by In_(2)O_(3)accelerates the transfer of photogenerated carriers and increases the surface temperature of the catalyst, thereby synergistically promoting the reaction from a kinetic perspective. This work ameliorates the kinetic and thermodynamic limitations of the photothermal catalytic CO_(2)hydrogenation process through rationally designing the electron transfer direction of the sandwich structured catalysts to parallel way.展开更多
基金supported by the National Natural Science Foundation of China(21976078 and 21773106)the National Key R&D Program of China(2016YFC0205900)+1 种基金the Natural Science Foundation of Jiangxi Province(20202ACB213001)National Engineering Laboratory for Mobile Source Emission Control Technology(NELMS2019A12)。
文摘Carbon dioxide and methane are two main greenhouse gases which are contributed to serious global warming.Fortunately,dry reforming of methane(DRM),a very important reaction developed decades ago,can convert these two major greenhouse gases into value-added syngas or hydrogen.The main problem retarding its industrialization is the seriously coking formation upon the nickel-based catalysts.Herein,a series of confined indium-nickel(In-Ni)intermetallic alloy nanocatalysts(In_(x)Ni@SiO_(2))have been prepared and displayed superior coking resistance for DRM reaction.The sample containing 0.5 wt.%of In loading(In_(0.5)Ni@SiO_(2))shows the best balance of carbon deposition resistance and DRM reactivity even after 430 h long term stability test.The boosted carbon resistance can be ascribed to the confinement of core–shell structure and to the transfer of electrons from Indium to Nickel in In-Ni intermetallic alloys due to the smaller electronegativity of In.Both the silica shell and the increase of electron cloud density on metallic Ni can weaken the ability of Ni to activate C–H bond and decrease the deep cracking process of methane.The reaction over the confined InNi intermetallic alloy nanocatalyst was conformed to the Langmuir-Hinshelwood(L-H)mechanism revealed by in situ diffuse reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS).This work provides a guidance to design high performance coking resistance catalysts for methane dry reforming to efficiently utilize these two main greenhouse gases.
基金supported by the National Key R&D Program of China (2021YFA1500704)the National Natural Science Foundation of China (22372116)。
文摘Photothermal catalytic CO_(2)hydrogenation is an effective means of utilizing carbon resources. However, it is severely limited in terms of kinetics and thermodynamics. Therefore, it is necessary to meticulously design catalysts to solve this problem. Herein, a sandwich structured Ni O@In Ni/In_(2)O_(3)is designed to intrinsically regulate the direction of photogenerated carriers transfer,resulting in a CO yield of 42.97 mmol g^(-1)h^(-1)(1290.3 μmol h^(-1)) with a selectivity near to 100%. In Ni alloy favors the collection of photogenerated carriers by the parallel way and enhancement of the adsorption and activation of CO_(2)molecules. NiO grown on the surface of In Ni alloy not only improves the adsorption of H_(2)and provides sufficient H^(+)for the reaction, but also makes In Ni alloy more stable during the reaction process. The photothermal effect caused by In_(2)O_(3)accelerates the transfer of photogenerated carriers and increases the surface temperature of the catalyst, thereby synergistically promoting the reaction from a kinetic perspective. This work ameliorates the kinetic and thermodynamic limitations of the photothermal catalytic CO_(2)hydrogenation process through rationally designing the electron transfer direction of the sandwich structured catalysts to parallel way.
