Mesoporous Silica Supported Perovskite Oxides for Low Temperature Thermochemical CO 2 Conversion
Mesoporous Silica Supported Perovskite Oxides for Low Temperature Thermochemical CO 2 Conversion
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用于低温热化学CO 2 转化的介孔二氧化硅负载钙钛矿氧化物
DOI：
10.1002/cctc.202001216
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发表时间：
2020
期刊：
影响因子：
4.5
通讯作者：
Kuhn, John N.
中科院分区：
文献类型：
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作者：
Brower, Jeremy C.;Hare, Bryan J.;Bhethanabotla, Venkat R.;Kuhn, John N.
在这项研究中，高产量的CO报道从CO2使用二氧化硅（SiO2）支持的钙钛矿氧化物，La0.75Sr0.25FeO3（LSF），复合材料在逆水煤气变换化学循环（RWGS-CL）过程。在将SBA-15添加到钙钛矿溶胶-凝胶前体溶液中时形成的材料的XRD图案表明在复合材料中成功形成了正交钙钛矿氧化物结构。通过CO2化学吸附和XPS测量验证了在SBA-15中添加50质量%的LSF的总表面积增加了约300%，并且钙钛矿氧化物微晶的表面可及性。通过在700 °C下的六个连续RWGS-CL循环，与纯LSF相比，复合材料实现了高达10倍的CO产率增加（0.35mmol CO/gLSF）。在这些RWGS-CL循环之后，XRD Scherrer分析表明复合材料中的钙钛矿氧化物的微晶尺寸减小。这种合成负载型钙钛矿氧化物的方法预计对RWGS-CL的大规模CO2转化有价值。
In this study, high yields of CO are reported from CO2using the silica (SiO2) supported perovskite oxide, La0.75Sr0.25FeO3(LSF), composites in the reverse water gas shift chemical looping (RWGS‐CL) process. XRD patterns of materials formed upon adding SBA‐15 to the perovskite sol‐gel precursor solution indicated successful formation of an orthorhombic perovskite oxide structure in the composites. The total surface area increased by ∼300 % with the addition of 50 % LSF to SBA‐15 by mass and surface accessibility of perovskite oxide crystallites was verified by CO2chemisorption and XPS measurements. Composite materials achieved up to a factor of 10 increases in CO yields (∼3.5 vs 0.35 mmol CO/gLSF) compared to pure LSF through six consecutive RWGS‐CL cycles at 700 °C. Following these RWGS‐CL cycles, XRD Scherrer analyses showed that the perovskite oxide in the composite material decreased in crystallite size. This approach to synthesis of supported perovskite oxides is expected to be valuable for large‐scale CO2conversion by RWGS‐CL.