查看更多>>摘要：A multi-layered nanostructured Ni/CeO2 catalyst was synthesized through a facile one-pot hydrothermal reaction. The influence of catalyst pre-treatment was investigated as an efficient and easy strategy to improve its catalytic activity. The catalyst exhibited stable above 90% CO2 and 85% CH4 reactant conversions and high product H2/CO ratio (close to 0.95) for DRM at 700 °C for 24 h, with a two-step pre-treatment of the catalyst (H2 reduction followed by CO2 oxidation). This can be ascribed to the multi-layered structure of CeO2 support, enhancing of exposed metal-support interface between Ni and the CeO2 and formation of carbon and oxygen species on the catalyst surface, as indicated by characterizations of H2-TPR, XPS, XRD, FTIR and HAADF-STEM. The simple synthesis and pre-treatment method of such Ni/CeO2 catalyst with high DRM performance offers new opportunities for CeO2 application into DRM reaction as a promising support material.
查看更多>>摘要：Carbon neutrality is spurring worldwide impetus on the exploration of CO2 hydrogenation to methanol, but groundbreaking catalyst presents a grand challenge. An outstanding InNi3C_(0.5)/Fe3O4 catalyst is tailored by finely tuning the electronic metal-support interaction (EMSI) that is controlled by Fe3O4 precursor. The one using Fe3O4-N (from ferric nitrate) stands out against the ones using Fe3O4-A (ferrous acetate) and Fe3O4-C (ferric chloride), achieving a turnover frequency (421.6 h~(-1)) 2.3-3.1 times as high as that of the two others. There is a correlation between the oxygen deficiency of Fe3O4 and the EMSI-governed activity. The EMSI effect is enhanced substantially by the highly oxygen-deficient Fe3O4-N. Enhanced EMSI makes InNi3C_(0.5) electron-enriched and thus enables CO2 to be dissociated easily. The InNi3C_(0.5)/Fe3O4-N achieves a high methanol space time yield of 2.60 g_(MeOH) g_(cat)~(-1) h~(-1) with 92.0% methanol selectivity at 325 °C and 6.0 MPa. This catalyst is also highly anti-sintering and anti-sulfur poisoning.
查看更多>>摘要：Tuning Fischer-Tropsch synthesis products of metallic Co-based catalysts from paraffins to value-added olefins chemicals attracts great attention but remains challenging. Herein, we succeed in designing the carbon layers confined cobalt metal core-shell nanocatalyst (Co@C) via a reduction-carburization-pyrolysis (RCP) pretreatment of Co/SiO2, which exhibits highly efficient for Fischer-Tropsch to olefins (FTO) with negligible Water-Gas-Shift activity. At 250 °C and 5 bar, 56.4 % of olefins selectivity and limited CO2 selectivity (5.8 %) are achieved for Mn-promoted Co@C nanocatalyst with at least 200 h of stability running. The electronic effect of carbon layers and Mn promoter as well as the confinement structure tailor the local chemical environment and weaken the hydrogenation ability of Co metal sites, thus improving the selectivity toward olefins while largely reducing the formation of CH4 and CO2. This work develops an effective strategy for the rational design of highly active and stable metallic Co-based FTO catalysts with high carbon efficiency.
查看更多>>摘要：The authors regret there is a correction about the electrolyte used in the NRR experiment. The experimentally used electrolyte is K2CO3 rather than K2SO4. This correction does not affect the discussion and conclusions of the original article. The authors would like to apologize for this error and any inconvenience caused [1].
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