Nanowire-Based Materials as Coke-Resistant Catalyst Supports for Dry Methane Reforming

Catalysts

卷:11

Sivakumar Vasireddy¹  Vivekanand Kumar¹  Mahendra Sunkara²  Apolo Nambo²  JacekB. Jasinski²  Veerendra Atla²  Sreedevi Upadhyayula³ 

[1] Advanced Energy Materials, LLC., 311 E Lee Street, Louisville, KY 40208, USA;

[2] Conn Center for Renewable Energy Research and Department of Chemical Engineering, University of Louisville, Louisville, KY 40292, USA;

[3] Department of Chemical Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India;

关键词: titania;    CO₂;    DMR;    nanowire;    methane;    coke;   

DOI  :  10.3390/catal11020175

来源: DOAJ

【 摘 要 】

In this paper, nanowire-supported catalysts loaded with nickel are shown to be coke resistant compared to nanoparticle-supported catalysts. Specifically, Ni-loaded titania-based nanowire catalysts were tested with the dry methane reforming process in a laboratory-scale continuous packed-bed atmospheric reactor. The CO₂ conversion rate stayed above 90% for over 30 h on stream under coke-promoting conditions, such as high flow rates, low temperatures, and a high ratio of CH₄ to CO₂. The coke (C_xH_y, x>>y) on the spent catalyst surface for both nanowire- and nanoparticle-supported catalysts was characterized by TGA, temperature-programmed reduction (TPR), and electron microscopy (SEM/TEM/EDS), and it was revealed that the types of carbon species present and their distribution over the morphology-enhanced materials played a major role in the deactivation. The CO₂ conversion activity of Ni supported on titania nanoparticles was reduced from ~80% to less than 72% in 30 h due to the formation of a graphitic coke formation. On the other hand, Ni particles supported on nanowires exhibited cube-octahedral morphologies, with a high density of non- (111) surface sites responsible for the increased activity and reduced graphitic coke deposition, giving a sustained and stable catalytic activity during a long time-on-stream experiment.

【 授权许可】

Unknown