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The electrocatalytic activity of the PtAu nanoparticles supported on ZSM-5 zeolite for the electrooxidation of ethanol has been investigated. The PtAu nanoparticles with a Pt/Au ratio of 1:1 were synthesized by the wet chemical co-reduction method and then deposited on ZSM-5 zeolite. Characterization of PtAu/ZSM-5 showed irregular chains and nets of the PtAu nanoparticles on the ZSM-5 zeolite surface, the alloy structure of PtAu, the variation in the lattice parameters of Pt and Au, and the electronic interaction between PtAu and ZSM-5 zeolite. The PtAu/ZSM-5 catalyst has high activity and stability for ethanol oxidation in alkaline solution. For instance, the peak intensity for PtAu/ZSM-5 is more than 2 times those for PtAu/C and Pt/ZSM-5. In addition, Pt/ZSM-5 and Au/ZSM-5 also show high catalytic activity compared to Pt/C and Au/C, respectively. The results indicate the promising applications of ZSM-5 zeolites as support materials for electrocatalysts and the superiority of the bimetallic PtAu over the monometallic Pt or Au in the catalytic activity.

In this study, the passivation mechanism of three azole inhibitors with different functional groups, benzotriazole (BTA), 5-methylbenzotriazole (TTA), 1-H carboxyl benzotriazole (CBT), on cobalt in H 2 O 2 based slurry were investigated. Results showed that cobalt (Co) has the highest removal rate (RR) and static etching rate (SER) in the solution without inhibitors, and RR and SER of Co decreased when three inhibitors were added to the reference solution respectively. However, compared with BTA and TTA, CBT showed the strongest passivation effect. Through the single frequency EIS experiments and X-ray photoelectron spectroscopy (XPS) measurements analysis, all three azole inhibitors can react with Co 2+ to form insoluble networked nanoparticles on the Co surface, but CBT had the thickest passivation film, which was inferred that the carboxyl group on the CBT can not only increase the coverage area on the Co surface like the methyl group, but also the oxygen on the carboxyl group can chemically adsorb on the Co surface like the N 17 on the imidazole ring. Moreover, TTA showed better passivation effect than BTA due to the existence of the methyl on TTA, which can increase the coverage area on Co surface and prevent the polishing slurry from contacting Co surface.