Topics in Catalysis 

About: Topics in Catalysis is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Catalysis & Adsorption. It has an ISSN identifier of 1022-5528. Over the lifetime, 3944 publications have been published receiving 114562 citations.

Instability of Supported Platinum Nanoparticles in Low-Temperature Fuel Cells

Abstract: This paper discusses the mechanisms of surface area loss of supported platinum (Pt) electrocatalysts in low-temperature fuel cells. It is argued that submonolayer dissolution of Pt nanoparticles governs the surface area loss at high voltages by increasing the loss of Pt from carbon and coarsening of Pt nanoparticles on carbon.

Platinum monolayer fuel cell electrocatalysts

Abstract: We describe a new class of electrocatalysts for the O2 reduction, and H2 and methanol oxidation reactions, consisting of a monolayer of Pt deposited on a metal or alloy carbon-supported nanoparticles. These electrocatalysts show up to a 20-fold increase in Pt mass activity compared with conventional all-Pt electrocatalysts. The origin of their increased activity was identified through a combination of experimental methods, employing electrochemical and surface science techniques, X-ray absorption spectroscopy, and density functional theory calculations. The long-term tests in fuel cells demonstrated excellent stability of the anode and good stability of the cathode electrocatalysts. We also describe the stabilization of Pt electrocatalysts against dissolution under potential cycling regimes effected by a submonolayer of Au clusters deposited on Pt surfaces. These new electrocatalysts promise to alleviate some of the major problems of existing fuel cell technology.

Impact of Zeolites on the Petroleum and Petrochemical Industry

Abstract: The general features of zeolites that led to their widespread use in oil refining and petrochemistry are highlighted as well as the details of their impact on selected processes. The analysis of the catalyst market and the position of zeolites therein is a good indication of their strategic importance. Zeolites have brought many disruptive changes to these fields (e.g. FCC). They impacted also these industries in an equally important way, although more subtle, by incremental improvement of processes. The new and vast challenges facing oil refining and petrochemistry as well as the managed transition to sustainable environmental benign transport fuel industries and chemical industries will require creative science and technologies. Zeolites offer the basis of many of these technological solutions provided efficient and balanced cooperations between industry and academia are further developed.

Heterogeneous photocatalysis: state of the art and present applications In honor of Pr. R.L. Burwell Jr. (1912–2003), Former Head of Ipatieff Laboratories, Northwestern University, Evanston (Ill).

Abstract: In the present paper, the basic fundamentals of photocatalysis are explained with the influence of the five main parameters which govern the kinetics: (i) mass of catalyst, (ii) wavelength, (iii) partial pression and/or concentrations of reactants, (iv) temperature (at a second degree) and (v) the radiant flux. The main types of photocatalytic reactions presently described (all performed at room temperature) concern (i) the selective mild oxidation of hydrocarbons, (ii) the hydrogen production and (iii) the total oxidation reactions of organics in presence of water. The last point constitutes the ensemble of the last recent developments in photocatalysis. Most of organic contaminants, including dangerous pesticides, can be easily totally degraded and mineralized.

Aromatic Production from Catalytic Fast Pyrolysis of Biomass-Derived Feedstocks

Abstract: The conversion of biomass compounds to aromatics by thermal decomposition in the presence of catalysts was investigated using a pyroprobe analytical pyrolyzer The first step in this process is the thermal decomposition of the biomass to smaller oxygenates that then enter the catalysts pores where they are converted to CO, CO2, water, coke and volatile aromatics The desired reaction is the conversion of biomass into aromatics, CO2 and water with the undesired products being coke and water Both the reaction conditions and catalyst properties are critical in maximizing the desired product selectivity High heating rates and high catalyst to feed ratio favor aromatic production over coke formation Aromatics with carbon yields in excess of 30 molar carbon% were obtained from glucose, xylitol, cellobiose, and cellulose with ZSM-5 (Si/Al = 60) at the optimal reactor conditions The aromatic yield for all the products was similar suggesting that all of these biomass-derived oxygenates go through a common intermediate At lower catalyst to feed ratios volatile oxygenates are formed including furan type compounds, acetic acid and hydroxyacetaldehyde The product selectivity is dependent on both the size of the catalyst pores and the nature of the active sites Five catalysts were tested including ZSM-5, silicalite, beta, Y-zeolite and silica–alumina ZSM-5 had the highest aromatic yields (30% carbon yield) and the least amount of coke