Highly thermally stable multi-porous calcium aluminum hydrotalcite catalyst for efficient carbonate synthesis
Highly thermally stable multi-porous calcium aluminum hydrotalcite catalyst for efficient carbonate synthesis
复制标题
用于高效碳酸盐合成的高热稳定性多孔钙铝水滑石催化剂
DOI：
10.1016/j.fuel.2022.125696
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发表时间：
2022
期刊：
影响因子：
7.4
通讯作者：
Shi Lei
中科院分区：
文献类型：
--
作者：
Deng Wenjie;Yao Jie;Shi Lei
在碳中和时代的背景下，通过化学催化转化温室气体CO2是一种强有力的手段。利用CO2和石油衍生的环氧烷烃为原料生产高价值的碳酸盐物质被认为是一条绿色、经济的碳减排和能源转型之路。我们发现了一种多孔钙铝水滑石材料（Ca-Al HT），并发现其对酯交换反应（碳酸酯合成中的一个重要反应）表现出优异的催化能力。不同于可溶性金属氢氧化物和有机卤化物盐等均相碱性催化剂，以及众所周知的固体碱性催化剂CaO，这些催化剂难以回收，并且在长期催化过程中会严重失活，在4000 min的有效催化过程中，Ca-Al HT催化剂中稳定的Ca 12 Al 14 O33晶相表现出更稳定的催化性能（63%转化率和100%选择性）。Ca 12 Al 14 O33的特殊晶相结构即使在900 °C的高温下也保持稳定。而CaO作为参比催化剂对催化体系中的微量H_2O非常敏感，并立即失活。Ca-Al HT具有超强的碱强度、大的碱量和多级孔道系统的快速传质是其优异催化性能的主要原因。
In the context of a carbon–neutral era, conversion of greenhouse gas CO2via chemical catalysis is a powerful means. Using CO2and petroleum-derived alkylene oxide as the raw materials to produce high-value carbonate substances has been considered a green and economic path for carbon reduction and energy transition. We discovered a multi-porous calcium aluminum hydrotalcite material (Ca-Al HT), and found that it performs excellent catalytic ability on transesterification (an important reaction in the synthesis of carbonates). Being different from homogeneous basic catalysts such as soluble metal hydroxides and organic halide salts, and well-known solid basic catalyst CaO, which are difficult to recycle and suffer severe deactivation in long-term catalytic process, the robust Ca12Al14O33crystal phase in Ca-Al HT catalyst behaves much more stable catalytic performance during 4000 min efficient catalysis (63 % conversion and 100 % selectivity). The special crystal phase structure of Ca12Al14O33remains stable at even a very high temperature of 900 °C. In contrast, CaO as the reference catalyst is very sensitive to trace H2O in catalytic system, and deactivates immediately. The outstanding catalytic ability of Ca-Al HT is attributed to its super-strong alkali strength, large alkali amount, and quick mass transfer originating from the hierarchical pore system.