An electrode catalyst layer for a fuel cell includes a catalyst/support composite including a support and a catalyst supported thereon. The support contains a titanium oxide. The surface of the catalyst/support composite has an oxide of at least one element selected from the group consisting of niobium, tantalum, zirconium, and silicon. The ratio A2/A1 is from 0.35 to 1.70, wherein A1 is the atomic ratio of titanium on a surface of the catalyst layer and A2 is the atomic ratio of a total of niobium, tantalum, zirconium, and silicon on the surface of the catalyst layer, A1 and A2 being measured by X-ray photoelectron spectroscopy. The titanium oxide preferably has a composition TiOx (0.5 ≤ x < 2).

This application relates to new process that utilizes electrodes that incorporate acids that facilitate upgrading of methane and other low molecular weight alkanes to higher order hydrocarbon molecules, such as paraffins, olefins, and aromatics, at temperatures less than 250° C. A primary focus of the invention includes methane conversion to ethylene. The first step of the process includes acid containing electrodes that facilitate the activation of the alkane in the anode layer of the electrochemical reactor. Subsequent steps include the separation of protons from produced longer chain hydrocarbons followed by subsequent electrochemical reduction of the protons to yield hydrogen at the cathode or protons combined with oxygen at the cathode to yield water. The reaction steps in the anode upgrade methane to higher order hydrocarbon products.

The invention is related to a carbon supported catalyst comprising a carbon-comprising support with a BET surface area in a range from 400 m.sup.2/g to 2000 m.sup.2/g, a modifier comprising at least one mixed metal oxide, comprising niobium and titanium, and/or a mixture, comprising niobium oxide and titanium oxide, a catalytically active metal compound, wherein the catalytically active metal compound is platinum or an alloy comprising platinum and a second metal or an intermetallic compound comprising platinum and a second metal, the second metal being selected from the group consisting of cobalt, nickel, chromium, copper, palladium, gold, ruthenium, scandium, yttrium, lanthanum, niobium, iron, vanadium and titanium.

The invention is further related to a process for preparing the carbon supported catalyst.

Provided is an electrode catalyst in which the contents of chlorine (Cl) species and bromine (Br) species are reduced to a predetermined level or lower, capable of exhibiting sufficient catalyst performance. The electrode catalyst has a core-shell structure including a support, a core part formed on the support and a shell part formed to cover at least a part of the surface of the core part. A concentration of bromine (Br) species of the electrode catalyst as measured by X-ray fluorescence (XRF) spectroscopy is 400 ppm or less, and a concentration of chlorine (Cl) species of the electrode catalyst as measured by X-ray fluorescence (XRF) spectroscopy is 900 ppm or less.

Provided is an electrode catalyst in which the contents of chlorine (Cl) species and bromine (Br) species are reduced to a predetermined level or lower, capable of exhibiting sufficient catalyst performance. The electrode catalyst has a core-shell structure including a support, a core part formed on the support and a shell part formed to cover at least a part of the surface of the core part. A concentration of bromine (Br) species of the electrode catalyst as measured by X-ray fluorescence (XRF) spectroscopy is 400 ppm or less, and a concentration of chlorine (Cl) species of the electrode catalyst as measured by X-ray fluorescence (XRF) spectroscopy is 900 ppm or less.

To provide electrode catalyst (core-shell catalyst) having an excellent catalyst activity which contributes to lower the cost of the PEFC. The electrode catalyst has catalyst particles supported an a support. The catalyst particle has a core part containing simple Pd and a shell part containing simple Pt. A percentage R.sub.C (atom %) of the carbon of the support and a percentage R.sub.Pd (atom %) of the simple Pd in an analytical region near a surface measured by X-ray photoelectron spectroscopy (XPS) satisfy the conditions of the following equation (1): 2.15≦[100×R.sub.Pd/(R.sub.Pd+R.sub.C)].

To provide electrode catalyst (core-shell catalyst) having an excellent catalyst activity which contributes to lower the cost of the PEFC. The electrode catalyst has catalyst particles supported an a support. The catalyst particle has a core part containing simple Pd and a shell part containing simple Pt. A percentage R.sub.C (atom %) of the carbon of the support and a percentage R.sub.Pd (atom %) of the simple Pd in an analytical region near a surface measured by X-ray photoelectron spectroscopy (XPS) satisfy the conditions of the following equation (1): 2.15≦[100×R.sub.Pd/(R.sub.Pd+R.sub.C)].

A non-aqueous fuel cell catalyst includes a carbon support medium; a coating layer comprising a proton-conducting polymer including a phosphoric acid group coated on a surface of the carbon support medium; and a support member comprising platinum or a platinum alloy supported on the coating layer.

This anode catalyst layer for a fuel cell contains electrode catalyst particles, a carbon carrier on which the electrode catalyst particles are loaded, water electrolysis catalyst particles, a proton-conducting binder, and graphitized carbon. The graphitized carbon has a bulk density of 0.50/cm.sup.3 or less.

A unit cell of a fuel cell may include: a membrane-electrode assembly including a proton exchange membrane, an anode electrode fastened to a first face of the proton exchange membrane, a first flow guide plate positioned facing the anode electrode and including at least one flow channel having a fuel inlet zone, a median flow zone and a fuel outlet zone. The anode electrode may have, at the fuel outlet zone, a tolerance to carbon monoxide pollution greater than its average tolerance to carbon monoxide pollution at the median flow zone and at the fuel inlet zone.