Li Ziwei, Kathiraser Yasotha, Ashok Jangam, Oemar Usman, Kawi Sibudjing
Department of Chemical and Biomolecular Engineering, National University of Singapore , Singapore 117585, Republic of Singapore.
Langmuir. 2014 Dec 9;30(48):14694-705. doi: 10.1021/la503340s. Epub 2014 Nov 26.
Ni@Ni-Mgphy (Ni-Mgphy = Ni-Mg phyllosilicate) core-shell catalysts were designed by hydrothermally treating Ni@SiO2 nanoparticles with magnesium nitrate salt. The porosity and basicity of the catalysts were easily tuned by forming Ni-Mgphy shell using Ni originating from Ni@SiO2 during the hydrothermal treatment process and Mg(NO3)2 as the Ni and Mg sources, respectively. Among Ni@Ni-Mgphy core-shell catalysts synthesized under different hydrothermal durations, the catalyst treated for 10 h achieved the best catalytic performance for CO2 reforming of CH4 reaction with stable CO2 and CH4 conversions of around 81% and 78%, respectively, within 95 h reaction duration at 700 °C. The high Ni accessibility, strong basicity, and high structural stability for Ni@Ni-Mgphy core-shell catalyst with 10 h treatment time accounted for its superb catalytic performance. This method to simultaneously tune the porosity and basicity of Ni@SiO2 core-shell nanoparticles demonstrates a general way to modify the properties of other silica based core-shell nanoparticles through treating them with different metal salts.
通过用硝酸镁盐水热法处理Ni@SiO₂纳米颗粒，设计出了Ni@Ni-Mgphy（Ni-Mgphy = Ni-Mg层状硅酸盐）核壳催化剂。在水热过程中，分别以Ni@SiO₂中的Ni和Mg(NO₃)₂作为Ni和Mg源形成Ni-Mgphy壳层，从而轻松调节催化剂的孔隙率和碱度。在不同水热时间下合成的Ni@Ni-Mgphy核壳催化剂中，经过10小时处理的催化剂在700℃、95小时的反应时间内，对CH₄与CO₂重整反应表现出最佳的催化性能，CO₂和CH₄的稳定转化率分别约为81%和78%。经过10小时处理的Ni@Ni-Mgphy核壳催化剂具有高Ni可及性、强碱性和高结构稳定性，这解释了其卓越的催化性能。这种同时调节Ni@SiO₂核壳纳米颗粒孔隙率和碱度的方法，展示了一种通过用不同金属盐处理来改变其他二氧化硅基核壳纳米颗粒性质的通用方法。
