中文摘要：

为进一步提高镍基催化剂的抗积炭能力,增强其甲烷二氧化碳重整反应性能,采用沉积沉淀法（DP）、共沉淀法（CP）和共浸渍法（CI）制备了NiCo/MgO催化剂。结合现代仪器分析表征技术,研究了制备方法对NiCo/MgO催化剂结构和抗积炭能力的影响。结果表明,与共沉淀法相比,沉积沉淀法制备过程为Ni2＋和Co2＋的完全水解沉淀提供了碱性环境,粒子的成核和生长速率相对较快,不存局部过饱和现象,所制备的催化剂具有良好的还原性、较小的颗粒粒径（9.7 nm）、良好的Ni/Co分散度（10.4%）和大的比表面积（68.1 m2/g）,从而具有优良的抗积炭性能。对于甲烷二氧化碳重整,DP催化剂上CH4和CO2转化率保持在88%和92%,与800℃下的热力学平衡转化率相近;同时,H2收率比CP和CI催化剂分别高约10%和43%,CO收率比CP和CI催化剂分别高约13%和42%,且稳定性更好。

英文摘要：

To enhance the performance of nickel-based catalysts in the reforming of CH4 with CO2 and alleviate the coke deposition,a series of NiCo/MgO catalysts were prepared by different methods,viz.,depositionprecipitation（ DP）,co-precipitation method（ CP） and co-impregnation（ CI）; the influence of preparation method on the structure and performance of NiCo/MgO catalyst was then investigated. The results show that during the deposition-precipitation process,CO（ NH2）2 as the precipitant could created an alkaline atmosphere for the complete hydrolysis of Ni2＋ and Co2＋ ions,leading to a relatively fast nucleation and growth of active species; however,oversaturation may occur during the co-precipitation process with NaOH and Na2CO3 as the precipitants. In comparison with the catalysts prepared by CP and CI,the NiCo/MgO-DP catalyst is provided with superior reduction capacity,smaller particle size（ 9.7 nm）,higher Ni/Co dispersion（ 10.4%） and larger specific surface area（ 68.1 m2/g） and then exhibits better resistance to coke deposition. Over the DP catalyst,the conversions of CH4 and CO2 at 800 ℃ reach 88% and 92%,respectively,much higher than those over the CP and CI catalysts; moreover,the DP catalyst also gives much higher yield of H2 and CO as well as better stability for methane reforming with CO2.