Decomposition of methanol on Rh and Au-Rh bimetallic nanoclusters supported by Al₂O₃/NiAl(100)

Guan-Jr Liao^1*, Zhen-He Liao¹, Po-Wei Hsu¹, Chia-Hsin Wang², Yaw-Wen Yang², Meng-Fan Luo¹

¹Department of Physics, National Central University, Taoyuan, Taiwan
²National Synchrotron Radiation Research Center, Hsinchu, Taiwan

* Presenter:Guan-Jr Liao, email:liaojohnnylkz01@gmail.com

We studied decomposition of methanol on Rh and Rh-Au nanoclusters supported on thin film Al2O3 under near-ambient pressure with photoelectron spectroscopy (PES), infrared reflection absorption spectroscopy (IRAS), and quadrupole mass spectrometer (QMS). The catalyzed decomposition of methanol has been widely studied since the reaction is applied to direct methanol fuel cells (DMFCs) and also serves as a source of hydrogen. In order to improve the performance of DMFCs and related products, understanding of a correlation between reactivity and structure of the catalysts is necessary. Rh nanoclusters exhibited size dependence toward methanol decomposition. The PES spectra of C 1s indicate that production of reaction per surface area increases with decreasing of deposition of Rh. The results were also confirmed by mass spectra. For Rh-Au nanoclusters, the PES spectra of C 1s show that the produced CO is adsorbed only on Rh. Compared with Au nanoclusters, Rh-Au nanoclusters enhance the methanol decomposition. The results are compared to those obtained under ultrahigh vacuum conditions.

Keywords: methanol decomposition, Rh-Au bimetallic nanoclusters, APXPS, IRAS