Design of Ni-ZrO2@SiO2 catalyst with ultra-high sintering and coking resistance for dry reforming of methane to prepare syngas

Dry reforming of methane (DRM) is an important reaction to prepare syngas (CO and H-2) and green hydrogen energy (H-2) and to use two abundant greenhouse gases (CO2 and CH4); the process is used in solar thermal-chemical storage and other kinds of high-temperature energy storage. However, the sintering and coking of the Ni-based catalysts represent two serious obstacles for the use of DRM in industrial applications. Herein, a novel core-shell catalyst with zirconia-modified nickel nanoparticles (NPs, Ni-ZrO2) as the cores and microporous silica as the shell (denoted as Ni-ZrO2@SiO2) was successfully designed and prepared via a one-pot facile strategy and used for the DRM reaction. The Ni-ZrO2@SiO2 catalyst showed the best time stability (240 h) under harsh reaction conditions (pure CH4 and CO2 as a feed gas, 800 degrees C, weight hourly space velocity (WHSV) = 18,000 ml g(cat).(-1) h (-1)) among the recently reported core-shell structured DRM catalysts and most importantly, no coking occurred. The catalyst also efficiently inhibited the sintering of the Ni NPs and thus greatly improved the resistance to coking due to the modification of the ZrO2 providing abundance of activated oxygen (Ni and ZrO2 was highly dispersed with each other, therefore, much amount of Ni-ZrO2 interface and perimeter was formed) and the special core-shell structure. Thanks to its ultra-high anti-sintering ability and resistance to carbon deposition, the Ni-ZrO2@SiO2 catalyst might have great potential for industrial applications.