镍基钙钛矿型催化剂的结构调控及其在甲烷干重整反应中的应用

钙钛矿材料在催化领域具有广泛的应用,其微观结构的调控对催化性能有显著的影响.我们采用柠檬酸配合法、溶胶凝胶法、燃烧法和浸渍法一系列不同的制备过程对镍基钙钛矿材料的结构进行调控,并将其应用于甲烷干重整反应,研究了制备方法对活性组分Ni的化学形态、Ni与基底的相互作用以及活性氧物种的调控,进而影响其催化活性和抗积碳能力.结果表明,燃烧法可以显著提高催化剂的结晶度,从而提高Ni与基底的相互作用以及表面氧物种的含量,使其具有较强的抗积碳能力.燃烧法合成的Ni基钙钛矿催化剂在CH4∶CO2=1.25∶1,800℃的条件下反应300 h后,积碳量仅为1.0%,而在同样条件下浸渍法合成的催化剂积碳量则高达14.6%.

Structure Control of Nickel-Based Perovskite Catalyst and Its Application in Methane Dry Reforming

Perovskite materials have a wide range of applications in the field of catalysis, and the regulation of their microstructure has a significant impact on catalytic performance. In this work, a series of perovskite catalysts prepared by different methods as citric complex method(-cc), sol-gel method(-sg), combustion method(-c) and wet impregnation method(-wi) were applied to the methane dry reforming. The preparation method was used to investigate the chemical morphology of Ni, the interaction between Ni and the perovskite matrix, and the regulation of reactive oxygen species, which in turn affected the catalytic activity and coke resistance. Combined with modern instrumental analysis and characterization techniques, the results showed that the combustion method can significantly increase the crystallinity of the catalyst, the interaction between Ni particles and matrix and the content of surface oxygen species, making it a strong ability to resist carbon deposition. The catalyst prepared by combustion method did not deactivate over 300 h under harsh conditions as CH₄:CO₂=1.25:1, and the amount of carbon deposition was only 1.0%. While the amount of carbon deposited on the catalyst prepared by the wet impregnation method was up to 14.6% under the same conditions.