Catalyst for cyclic capturing and methanation of carbon dioxide by calcium oxide at constant temperature and preparation method and application of catalyst

The invention discloses a catalyst for cyclic capturing and methanation of carbon dioxide by calcium oxide at a constant temperature. Metal nickel is supported on CaO according to a supporting amountof 0.1 to 10 percent by weight; carbon dioxide is captured and absorbed at a specific temperature; by maintaining the temperature unchanged, circulating gas is switched into hydrogen, so that methanecan be selectively generated; the process can be cyclically carried out for multiple times; and the carbon dioxide capturing capacity and the methane selectivity of CaO are not obviously reduced. Thesystem is stable in performance, can cyclically capture and convert the carbon dioxide and is high in selectivity, low in price and environmentally friendly; and the required technological process issimple. 种氧化钙恒温下循环捕获二氧化碳并甲烷化的催化剂是在CaO上负载金属镍，其负载量为0.1-10wt%。在特定温度下捕获吸收二氧化碳，保持温度恒定，切换流通气为氢气，即有甲烷选择性生成，该过程可多次循环进行，氧化钙捕获二氧化碳能力及甲烷选择性无明显降低。该体系性能稳定，可循环捕获并转化二氧化碳，选择性高，价格低廉，环境友好，所需工艺流程简单。