The Fundamental Research Of Electrochemical Oxidation Of Methane With Nano-metal Catalyst In The Ionic Liquid Electrolyte

The conversion and detection of CH4is the main conditioned factor on thedevelopment of the Coal Bed Methane. CH4is the hydrocarbon with thesimplest structure. The construction of CH4is normal tetrahedron structure. Theenergy of C-H is439kJ/mol so that it’s steady in chemical and electrochemicalwhich is hard to convert. Nowdays, The research of oxidation of CH4forcus onliquid phrase catalytic oxidation because of its salvation, large contact areabetween liquid and gas which can obtain the best access of catalyst and reactant.This process routine has a disadvantage which is hard to separate solvent withthe product. The ionic liquid is often used as the electrolyte in electrochemicaloxidation because of its good electrical conductivity, low volatility, widelyelectrochemical window. It has strong acid which can promote the oxidation ofCH4. Aimed at the problem for lacking of study on the kinds of ionic liquid andnano-metal activate CH4as the electro-catalysts, this article developed the research on electro-chemical oxidation of CH4.Catalysts like Pt、Pd、Au nano-metal and Pt/Co、Pt/Ru、Pd/Au nano-alloymetal were prepared by the colloidal method and characterized by X-raydiffraction and X-ray photoelectron spectroscopy. The results indicated that theaverage particle size of catalysts which we prepared is12nm with high catalyticactivity which is uniformly distributed.In this paper, cyclic voltammetry was carried out to measure the activity ofelectrochemical oxidation of methane with varies of catalysts in different ionicliquid electrolytes. The results indicated that Pt, Pd, Au and Pd/Au, Pt/Co, Pt/Ruin the ionic liquid with [mim] could not oxidate the methane because of the lowsolubility. The solubility of CH4in ionic liquid with [Tf2N] is larger than otherswhich provide the basic condition of oxidation of CH4. Althrough [N8888][Tf2N]is the one with lowest chemical polarity, the solubility of CH4is larger but itsconductivity is not so good to provide the environment for CH4to adsorb andoxidate.[C4mpy][Tf2N] is a perfect electrolyte with wide electrochemicalwindow and steady chemical properties. Only the combined activate of[C4mpy][Tf2N] and Pt can break C-H in CH4, and the peak current of methaneincreased with the increase temperature which is easier to oxidate CH4.This study also improved the ionic liquid to control the product, enchancedthe reativity of the oxidation of methane. The cyclic voltammetry was carriedout to measure the activity of electrochemical oxidation of methane with Pt inthe mixed electrolyte. FI-IR was carried out to measure the product. The results indicated that in the electrolyte of [C4mpy][Tf2N] and H2SO4, the spike potentialfor electrocatalytic oxidation of methane changed. This mixture solvent can beused in the ionic liquid sensors for methane detection to increase the sensitivity.This article provided the important thread of electro-chemical oxidation ofCH4and established the foundation of selection and optimization of ionic liquid.The principle and method of experiment are meaningful which can be used toimprove the sensibility of methane sensor and promote the development ofelectro-oxidation of methane.