Ce stabilized Ni–SrO as a catalytic phase transition sorbent for integrated CO 2 capture and CH 4 reforming
Ce stabilized Ni–SrO as a catalytic phase transition sorbent for integrated CO 2 capture and CH 4 reforming
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Ce 稳定的 Ni−SrO 作为催化相变吸附剂，用于集成 CO 2 捕获和 CH 4 重整
DOI：
10.1039/d1ta09967a
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发表时间：
2022
影响因子：
11.9
通讯作者：
Li, Fanxing
中科院分区：
文献类型：
--
作者：
Gu, Haiming;Gao, Yunfei;Iftikhar, Sherafghan;Li, Fanxing
从烟道气中捕集二氧化碳与甲烷干重整的集成代表了一种有吸引力的CO2利用方法。选择合适的双功能材料作为催化剂/吸附剂是关键。本文报道了Ni修饰和CeOx稳定的SrO（SrCe0.5Ni0.5）作为一种多功能相变催化吸附材料。采用TEM-EDX、XRD、原位XRD、CH_4-TPR和TGA等方法研究了CeOx对催化剂的形貌、结构、脱碳活性和循环稳定性的影响。在填充床反应器中进行循环过程测试。结果表明，SrNi吸附剂表面存在较大的Ni团簇，CeO 2的加入促进了Ni在SrNi吸附剂表面的均匀分布。此外，Ce-Sr相互作用促进了复杂的碳酸化/脱碳相转变，即SrCO 3 + CeO 2参与Sr 2CeO 4 + CO2，而不是传统的，简单的碳酸化/脱碳循环（例如SrCO 3参与SrO + CO2）。这种双置换结晶相变机制不仅调节碳酸化/煅烧热力学以促进SrCO 3在相对低的温度下分解，而且抑制吸附剂烧结。结果表明，利用CeO 2参与Ce 2 O3的氧化还原转变，该催化剂具有良好的活性和稳定性，甲烷转化率高达91%，CO2捕集效率大于72%，烟气中残余O2捕集效率接近100%。这提供了具有零焦炭沉积的强化工艺。此外，具有SrCe0.5Ni0.5的SLDRM具有通过CO2裂解产生浓缩CO的灵活性，同时共同产生具有可调H2/CO比的合成气。
Integration of carbon dioxide capture from flue gas with dry reforming of CH4 represents an attractive approach for CO2 utilization. The selection of a suitable bifunctional material serving as a catalyst/sorbent is the key. This paper reports Ni decorated and CeOx-stabilized SrO (SrCe0.5Ni0.5) as a multi-functional, phase transition catalytic sorbent material. The effect of CeOx on the morphology, structure, decarbonation reactivity, and cycling stability of the catalytic sorbent was determined with TEM-EDX, XRD, in situ XRD, CH4-TPR and TGA. Cyclic process tests were conducted in a packed bed reactor. The results indicate that large Ni clusters were present on the surface of the SrNi sorbent, and the addition of CeO2 promoted even distribution of Ni on the surface. Moreover, the Ce–Sr interaction promoted a complex carbonation/decarbonation phase-transition, i.e. SrCO3 + CeO2 ↔ Sr2CeO4 + CO2 as opposed to the conventional, simple carbonation/decarbonation cycles (e.g. SrCO3 ↔ SrO + CO2). This double replacement crystalline phase transition mechanism not only adjusts the carbonation/calcination thermodynamics to facilitate SrCO3 decomposition at relatively low temperatures but also inhibits sorbent sintering. As a result, excellent activity and stability were observed with up to 91% CH4 conversion, >72% CO2 capture efficiency and ∼100% residual O2 capture efficiency from flue gas by utilizing the CeO2 ↔ Ce2O3 redox transition. This renders an intensified process with zero coke deposition. Moreover, the SLDRM with SrCe0.5Ni0.5 has the flexibility to produce concentrated CO via CO2-splitting while co-producing a syngas with tunable H2/CO ratios.