Fabrication Of The Palladium-based Composite Nanocatalysts And Study Of Their Electrocatalytic Properties

The increasing consumption of traditional fossil fuels coupled with the serious environment crisis has stimulated the rapid development of renewable and clean energy technology.Fuel cells,with the features of high-energy,non-toxic and safe,have attracted an increasing notice for serving as promising energy conversion devices.Presently,in the fuel cells,the most common electrocatalysts are platinum?Pt?or Pt-based electrocatalysts.However,commercialization of fuel cells has been impeded by some objective factors: first,Pt is rarely reserved in nature,and widespread use of expensive metal-Pt is difficult to reduce the cost of fuel cells;second,Pt catalysts have vulnerability and instability towards carbon monoxide poisoning.Therefore,the urgent matter to address is to develop more advanced electrocatalysts: on the one hand,it is possible to replacing Pt with other accessible,multiple,less expensive fungible metals that contribute to lowering the cost;on the other,the as-prepared product should has a positive effect on the catalytic activity and durability.Palladium?Pd?is an appropriate fungible for Pt and holds the great promise for resolving the aforementioned challenges to apply fuel cells into practice because Pd is the most Pt-like material and it holds the similar ability with Pt.Comprehensive the above points,this paper employs different methods for preparation of a series of Pd composite catalysts,the morphology,composition and structure of Pd-based catalysts were studied,catalyst of methanol,ethanol and ethylene glycol was studied in detail the electric catalytic performance,the main research contents are as following:?1?A series of PdPbPt nanocomposites with different ratios have been synthesized through a facile one-pot method with NaBH₄ as a reducing agent and the assistance of PVP,the morphology,structure and composition of PdPbPt nanocomposites were characterized through TEM,HRTEM and XPS.Meanwhile,we also explore the effect of PdPbPt nanocomposites with different ratios,the result shows that when the ratio of Pb : Pd : Pt is 1:1:0.027,the PdPbPt nanocomposite has the best electrocatalyst activity.?2?The PdCu electrocatalyst was fabricated successfully by chemical reduction method.SEM and TEM results show that network PdCu nanocomposite has three-dimensional?3D?porous structure.The special 3D network PdCu nanocatalyst greatly enhanced the electrochemically active surface area and is benificial to catalytic activities.What's more,the electrochemical tests also reveal that 3D PdCu electrical nanocatalysts possess excellent catalytic activity and anti-poisoning ability toward ethanol oxidation reactions in alkaline solution.?3?Take AA as the reducing agent,CTAB as assistant agent,Pd Ru electrocatalyst was fabricated successfully via a facile wet-chemical strategy.Through TEM and HRTEM,the results reveal that the as-obtained Pd Ru nanocrystals exhibit a distinct cubic shape with concave structures,which can enhance the contact areas with electrolyte.The results of cycle voltammetries and successive cycle voltammetries of 1000 cycles reveal that concave Pd Ru nanocubes exhibit greatly enhanced catalytic activity and stability towards ethylene glycol oxidation reactions in alkaline solution,which may on account of the special morphology of catalysts.