Dry reforming of methane is an important process for the utilization of CO₂ and to get valuable synthesis gas. Alkaline earth metal substituted MZr_1-xNi_xO_3-δ perovskites were synthesized by citrate gel method, characterized and evaluated for dry reforming methane. Characterization results show that the type of alkaline earth substituted at the A site of the perovskite oxide plays an important role in terms of structure, basicity, oxygen deficiency and Ni dispersion. Calcium substituted CaZr_0.8Ni_0.2O_3-δ catalyst shows superior activity in terms of high CH₄ and CO₂ conversion, while maintaining the activity even after 500 h of reaction. Mechanistic investigations were carried out using transient pulse experiments and insitu FTIR-diffuse reflectance spectroscopy. These experiments reveal that redox property and basicity play important role in activation and sustaining the reforming reaction. Insitu FTIR measurements show that surface hydroxyl groups of the support are vital for high activity and durability of CaZr_0.8Ni_0.2O_3-δ catalyst. XRD and TGA analysis of catalysts after reaction show the structures are retained, but peaks pertaining to coke were observed on SrZr_0.8Ni_0.2O_3-δ and BaZr_0.8Ni_0.2O_3-δ catalysts. On the otherhand, CaZr_0.8Ni_0.2O_3-δ catalyst had only amorphous carbon even after 500 h of reaction. HRTEM studies revealed that SrZr_0.8Ni_0.2O_3-δ and BaZr_0.8Ni_0.2O_3-δ catalysts deactivated mostly due to the formation of carbon nanotubes with Ni embedded in them. Raman and XPS analysis helped in identifying types of coke precursors present on the catalysts. The investigation also illustrate that type of carbon formed depends on the basicity of perovskite oxide, metal to support interaction, Ni crystallite size, surface hydroxyl groups and oxygen defects. This study clearly demonstrated that CaZr_0.8Ni_0.2O_3-δ is an excellent catalyst for dry reforming reaction with long life.

甲烷的干重整是利用CO ₂和获得有价值的合成气的重要过程。用柠檬酸盐凝胶法合成了碱土金属取代的MZr _1-x Ni _x O3 _-δ钙钛矿，表征并进行了甲烷干法重整。表征结果表明，在钙钛矿氧化物的A位上取代的碱土的类型在结构，碱度，氧缺乏和Ni分散方面起着重要作用。钙取代的CaZr _0.8 Ni _0.2 O3 _-δ催化剂在高CH ₄和CO ₂方面显示出优异的活性转化，同时即使经过500小时反应仍保持活性。使用瞬态脉冲实验和原位FTIR漫反射光谱法进行了机理研究。这些实验表明，氧化还原性质和碱性在活化和维持重整反应中起重要作用。原位FTIR测量表明，载体的表面羟基对于CaZr _0.8 Ni _0.2 O3 _-δ催化剂的高活性和耐久性至关重要。反应后催化剂的XRD和TGA分析表明其结构得以保留，但在SrZr _0.8 Ni _0.2 O3 _-δ和BaZr _0.8 Ni _0.2上观察到了与焦炭有关的峰。O3 _-δ催化剂。另一方面，即使在反应500小时后，CaZr _0.8 Ni _0.2 O3 _-δ催化剂也仅具有无定形碳。HRTEM研究表明SrZr _0.8 Ni _0.2 O3 _-δ和BaZr _0.8 Ni _0.2 O3 _-δ催化剂失活主要是由于形成了嵌入了Ni的碳纳米管。拉曼和XPS分析有助于确定催化剂上存在的焦炭前体类型。研究还表明，形成的碳的类型取决于钙钛矿氧化物的碱性，支持相互作用的金属，Ni微晶尺寸，表面羟基和氧缺陷。这项研究清楚地表明，CaZr _0.8 Ni _0.2 O3 _-δ是长寿命干重整反应的优良催化剂。