Facile synthesis of multi-layered nanostructured Ni/CeO2 catalyst plus in-situ pre-treatment for efficient dry reforming of methane

Efficient Calcium Looping-Integrated Methane Dry Reforming by Dual Functional Aerosol Ca–Ni–Ce Nanoparticle Clusters

“…The results show that an enhanced reducibility of Ni (i.e., a lower T β ) reduces the activation energy for CH 4 conversion (i.e., E a ≈ 4 × 10 –12 T β 5.6789 ; details are shown in Figure S9 of the Supporting Information) and therefore lowers the onset temperature ( T s ) of the DRM reaction. Apart from improving the reducibility of the material, the addition of a proper amount of CeO 2 enhanced the catalytic performance through the increase of its redox abilities. , The formation of Ca–Ni–Ce interfaces provided additional active sites for the CH 4 excitation. ,,,,, Note that the turnover frequencies (TOF CH 4 ) of the synthesized DFMs are summarized in Table , showing that an optimal TOF CH4 was achievable when Ni/Ce = 1.5.…”

“…Environmental pollution has become a critical problem to be solved expeditiously in today’s world. The significant increment of carbon dioxide concentration in the atmosphere due to industrial activities has led to environmental challenges, especially climate change. − Several measures have been proposed worldwide to reduce CO 2 emissions to mitigate global warming. Nowadays, carbon capture and utilization (CCU) technologies are gaining increasing attention as excess CO 2 can be converted into valuable chemical feedstocks via different reaction routes. , Opposed to the carbon capture and storage processes, in a typical CCU process, CO 2 captured from flue gases can be utilized directly in the downstream processes, avoiding the additional cost for storage. ,,, Among different CCU technologies, calcium looping (CaL) is a sorbent-based CCU strategy, which captures and utilizes CO 2 via the reversible carbonation/calcination process, ,,− according to eq normalC normala normalO ( s ) + normalC normalO 2 ( g ) ↔ normalC normala normalC normalO 3 ( s ) …”

“…Dry reforming of methane (DRM) has been extensively studied as it involves the reaction between two critical greenhouse gases (i.e., CO 2 and CH 4 ), coupling to the production of syngas (i.e., H 2 and CO). ,,, By integrating CaL with methane dry reforming, CO 2 can be captured by CaO during the first carbonation step and react with CH 4 to produce syngas during the DRM step, ,,, as illustrated in eq normalC normala normalC normalO 3 ( s ) + normalC normalH 4 ( g ) ↔ normalC normala normalO ( s ) + 2 normalH 2 ( g ) + 2 normalC normalO ( g ) …”

“…Tian et al reported that Ca–Ni interfaces in the CaO–Ni material favored CH 4 dissociation and achieved 65% of CO 2 conversion at 800 °C; Hu et al incorporated thermally stable CeO 2 to CaO–Ni materials, resulting in 90% of CO 2 conversion at a relatively low temperature (650 °C); Kim et al used MgO–Al 2 O 3 as a support material to prepare CaO–Ni@MgO–Al 2 O 3 , where 99.9% of CO 2 conversion was achieved at 720 °C . Overall, the incorporation of catalyst promoters (e.g., ceria) has been shown to improve the activity and stability of the Ni-based catalyst. ,,,, The Ca–Ce and Ca–Ni–Ce interfaces provide alternative catalytic pathways to enhance carbonation and DRM, respectively, instead of using CaO and Ni alone. , …”

“…9 Overall, the incorporation of catalyst promoters (e.g., ceria) has been shown to improve the activity and stability of the Ni-based catalyst. 4,13,19,24,28 The Ca−Ce and Ca−Ni−Ce interfaces provide alternative catalytic pathways to enhance carbonation and DRM, respectively, instead of using CaO and Ni alone. 1,9 However, the present DFM prepared by the conventional approach (e.g., using a sol−gel-based coprecipitation method) possessed several drawbacks that limited the effectiveness of CO 2 conversion.…”