Mahboob Salar, Haghighi Mohammad, Rahmani Farhad
Chemical Engineering Faculty, Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz, Iran; Reactor and Catalysis Research Center (RCRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz, Iran.
Chemical Engineering Faculty, Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz, Iran; Reactor and Catalysis Research Center (RCRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz, Iran.
Ultrason Sonochem. 2017 Sep;38:38-49. doi: 10.1016/j.ultsonch.2017.02.039. Epub 2017 Mar 1.
The catalytic performance of nanostructured Ni-Co/AlO-ZrO catalysts, prepared by ultrasound-assisted impregnation method was examined in the dry reforming of methane. The effect of irradiation power and irradiation time have been studied by changing time (0, 20, 80min) and power of the sonication (30, 60, 90W) during the synthesis which resulted in different physiochemical properties of the nanocatalyst. The nanocatalysts were characterized by XRD, FESEM, PSD, EDX, TEM, TPR-H, BET, FTIR and TG analyses. Based on the characterization results, ultrasound treatment endowed the sample with more uniform and smaller nanoparticles; higher surface area, stronger metal-support interaction and more homogenous dispersion. Moreover, the analyses exhibited smaller particles with higher surface area and less population of particle aggregates at longer and highly irradiated nanocatalysts. The nanocatalyst irradiated at 90W for 80min (the longest irradiation time and the most intense power) showed a uniform morphology and a very narrow particles size distribution. More than 65% of particles of this nanocatalyst were in the range of 10-30nm. Activity tests demonstrated that employing ultrasound irradiation during impregnation improves feed conversion and products yield, reaching values close to equilibrium. Among sonicated nanocatalysts, with increasing power and time of irradiation, the nanocatalyst represents higher activity. The superior performance amongst the various bimetallic catalysts tested was observed over the catalyst with 90W and 80min ultrasonic irradiation which is stable in 24h time on stream test. The excellent anti-coking performance of this bimetallic catalyst, confirmed by TG and FESEM analyses of spent catalyst, is closely related to the promoting effect of sonication on the metal-support interaction, Ni dispersion and particle size; and probably, the synergy between metallic species.
通过超声辅助浸渍法制备的纳米结构Ni-Co/AlO-ZrO催化剂在甲烷干重整反应中的催化性能进行了研究。通过在合成过程中改变时间（0、20、80分钟）和超声功率（30、60、90瓦），研究了辐照功率和辐照时间的影响，这导致了纳米催化剂具有不同的物理化学性质。采用XRD、FESEM、PSD、EDX、TEM、TPR-H、BET、FTIR和TG分析对纳米催化剂进行了表征。基于表征结果，超声处理使样品具有更均匀、更小的纳米颗粒；更高的比表面积、更强的金属-载体相互作用和更均匀的分散性。此外，分析表明，在较长时间和高辐照的纳米催化剂中，颗粒更小，比表面积更高，颗粒聚集体数量更少。在90瓦下辐照80分钟（最长辐照时间和最强功率）的纳米催化剂呈现出均匀的形态和非常窄的粒径分布。该纳米催化剂超过65%的颗粒尺寸在10-30纳米范围内。活性测试表明，在浸渍过程中采用超声辐照可提高原料转化率和产物产率，达到接近平衡的值。在超声处理的纳米催化剂中，随着辐照功率和时间的增加，纳米催化剂表现出更高的活性。在24小时的连续流测试中，观察到在各种测试的双金属催化剂中，经90瓦和80分钟超声辐照的催化剂性能最佳且稳定。通过对失活催化剂的TG和FESEM分析证实，这种双金属催化剂优异的抗结焦性能与超声对金属-载体相互作用、Ni分散和粒径的促进作用密切相关；并且可能与金属物种之间的协同作用有关。
