tailieunhanh - Báo cáo hóa học: " Avoiding Loss of Catalytic Activity of Pd Nanoparticles Partially Embedded in Nanoditches in SiC Nanowires'

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Avoiding Loss of Catalytic Activity of Pd Nanoparticles Partially Embedded in Nanoditches in SiC Nanowires | Nanoscale Res Lett 2010 5 332-337 DOI S11671-009-9484-6 NANO EXPRESS Avoiding Loss of Catalytic Activity of Pd Nanoparticles Partially Embedded in Nanoditches in SiC Nanowires Xiao-Ning Guo Ru-Jing Shang Dong-Hua Wang Guo-Qiang Jin Xiang-Yun Guo K. N. Tu Received 28 September 2009 Accepted 28 October 2009 Published online 15 November 2009 to the authors 2009 Abstract Nanoditches from selective etching of periodically twinned SiC nanowires were employed to hinder the migration and coalescence of Pd nanoparticles supported on the nanowires and thus to improve their catalytic stability for total combustion of methane. The results show that the etched Pd SiC catalyst can keep the methane conversion of almost 100 while the unetched one has an obvious decline in the catalytic activity from 100 to 82 after ten repeated reaction cycles. The excellent catalytic stability originates from the limitation of the nanoditches to the migration and growth of Pd nanoparticles. Keywords SiC nanowires Selective etching Pd nanoparticles High catalytic stability Introduction Noble metal nanoparticles dispersed on inert supports usually exhibit high chemical activity in heterogeneous catalyst as well as fuel cell applications. However the . Guo . Shang . Wang . Jin . Guo State Key Laboratory of Coal Conversion Institute of Coal Chemistry 030001 Taiyuan People s Republic of China e-mail xyguo@ K. N. Tu Department of Materials Science and Engineering University of California at Los Angeles Los Angeles CA 90095-1595 USA e-mail kntu@ . Guo . Shang Graduate University of the Chinese Academy of Sciences 100039 Beijing People s Republic of China 0 Springer metal nanoparticles migrate and aggregate easily on the supports thus their chemical activity decreases rapidly. For example the growth of Pt nanoparticles in the cathode catalyst of fuel cell is one of the major factors resulting in the degradation of catalytic performance 1 2 . Au .