Facile synthesis of Ti-Mo2C/Ni-BTC metal-organic framework derived Pt-NiO/Ti-Mo2C supported on Vulcan carbon for electro-oxidation of methanol Tapan Kumar Ghosh and Gangavarapu Ranga Rao Department of Chemistry, Indian Institute of Technology Madras, Chennai-600036, India Email: grrao@iitm.ac.in The fuel cell is considered as a promising energy conversion device, which converts chemical energy into electricity. Among all, direct methanol fuel cells (DMFCs) with the merits of high energy density (4820 Wh L -1 ), high energy conversion efficiency, easy operation, low emission and fast mechanical refuelling possess great potential as energy conversion devices. Moreover, methanol is liquid at room temperature, economically viable, and easier to transport and store as compared to hydrogen (Energy density: 180 Wh L -1 ). Methanol oxidation reaction (MOR) is the basic anodic reaction involved in the DMFCs. In the present scenario, Pt is considered the most efficient catalyst for DMFCs. However, the efficiency of Pt is severely affected due to the formation of intermediate surface species (CO ads ), which block the active sites and prevents the methanol oxidation. Moreover, the high cost and scarcity of Pt have strongly limited the commercialization of DMFCs. Another strategy is to reduce the Pt concentration by alloying with other inexpensive metals (i.e. Ni, Cu, Co etc.) or by incorporating a minimum amount of Pt into transition metal oxide/carbides catalysts. The incorporation of a second metal ion facilitates the kinetics of MOR by providing additional active sites for the adsorption of oxophillic species (OH ads ), which further react with CO ads on the neighbouring Pt sites and remove as CO 2 . Hence, the development of highly efficient CO-poisoning-tolerant catalyst for MOR is crucial to optimize the efficiency of a DMFC. Herein, we have successfully synthesized Vulcan carbon supported Pt-based electrocatalyst (Pt-NiO/Ti-Mo 2 C/VC) using a Ti-Mo 2 C/ Ni-BTC metal-organic framework derived NiO/Ti-Mo 2 C under microwave-digested reflux method. The Pt-NiO/ Ti-Mo 2 C/VC with low Pt content (10 wt%) exhibited excellent methanol electro-oxidation in acidic media (0.5 M CH 3 OH+1 M H 2 SO 4 ) with very high current density of 30.8 mA cm -2 , and longer polarization time/stability (10800 s) than the commercial Pt/C (20 wt%) catalyst. The enhanced activity is due to the defective nature of the interface between Pt, NiO and Ti-Mo 2 C. References
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