Heterogeneous Catalysis on a Disordered Surface

We introduce a simple model of heterogeneous catalysis on a disordered surface which consists of two types of randomly distributed sites with different adsorption rates. Disorder can create a reactive steady state in situations where the same model on a homogeneous surface exhibits trivial kinetics with no steady state. A rich variety of kinetic behaviors occur for the adsorbate concentrations and catalytic reaction rate as a function of model parameters.Comment: 4 pages, gzipped PostScript fil

Heterogeneous Catalysis

A heterogeneous catalyst is a functional material that continually creates active sites with its reactants under reaction conditions. These sites change the rates of chemical reactions of the reactants localized on them without changing the thermodynamic equilibrium between the materials

Inverse opal ceria–zirconia: architectural engineering for heterogeneous catalysis

The application of inverse opal structured materials is extended to the ceria–zirconia (Ce_(0.5)Zr_(0.5)O_2) system and the significance of material architecture on heterogeneous catalysis, specifically, chemical oxidation, is examined

Improvement of Synergetic Effect In Heterogeneous Catalysis By Addition Of Metal Oxides

Over the past few years, synergetic effect has great importance in the heterogeneous catalysis structure. Synergetic effect provides the importance of the activity and stability of catalysis to produce desired product by improving the defects in the solid heterogeneous catalysis. These defects occur due to imperfection of the solid crystal lattices. And these defects can be improved by the addition of various metal oxides, which finally improve the synergetic effect or the defects in the heterogeneous catalysis. The metal oxide additives were found to influence the catalytic activity in the reaction, surface composition of the catalyst and the stability of catalysts during their operation. This paper reviews and assesses the effectiveness of different metal oxides additives in the heterogeneous catalysis activity and stability i.e. by improving synergetic effect in the heterogeneous catalysis. Keywords: synergy effect, encapsulation, mimic enzyme, BET,  coprecipitation, calcination.

Quasi-Stationary Distributions for Models of Heterogeneous Catalysis

We construct the quasi-stationary (QS) distribution for two models of heterogeneous catalysis having two absorbing states: the ZGB model for the oxidation of CO, and a version with noninstantaneous reactions. Using a mean-field-like approximation, we study the quasi-stationary surface coverages, moment ratios and the lifetime of the QS state. We also derive an improved, consistent one-site mean-field theory for the ZGB model.Comment: 18 pages, 13 figure

Heterogeneous Catalysis Transesterification of Waste Cooking Oil (WCO) and Parametric Optimization

Waste cooking oil (WCO) is considered to be a potential feedstock for biodiesel due to its low cost, availability in avoiding the food-for-fuel competition of the same oil resources, and also associated with WCO disposal. Hence, the WCO was chosen for this study to investigate the transesterification reaction of microwave energy pretreated WCO using heterogeneous catalyst derived from chicken bones from the calcination temperature of 900 °C (C900). WCO and catalyst characterization were performed. Two models; alkali heterogeneous catalysis transesterification and microwave energy pretreated alkali heterogeneous catalysis transesterification, were designed of 62 experiments to investigate the effect of five reaction variables; Methanol to oil molar ratio, catalyst concentration, reaction temperature, reaction time and microwave heating time. The interaction effects of reaction variables were studied using statistical tool of Central Composite Design (CCD) technique of Response Surface Methodology (RSM). It is found that reaction temperature and reaction time are the significant variables for heterogeneous catalysis transesterification whereas reaction time, microwave heating time and C900 concentration were dominant variables to the FAME yield. The optimum FAME yield of microwave energy pretreated transesterification was at 91.94 % and qualitatively higher than that of alkali heterogeneous catalysis transesterification which gained 98.308 %. The FAME yield conditions proved that microwave energy can improve the transesterification and enhance the product yield up to 3.38 times higher than alkali heterogeneous catalysis transesterification within a shorter length of tim

First-principles kinetic modeling in heterogeneous catalysis: an industrial perspective on best-practice, gaps and needs

Electronic structure calculations have emerged as a key contributor in modern heterogeneous catalysis research, though their application in chemical reaction engineering remains largely limited to academia. This perspective aims at encouraging the judicious use of first-principles kinetic models in industrial settings based on a critical discussion of present-day best practices, identifying existing gaps, and defining where further progress is needed

Application of Carbon Nanomaterials as Supports in Heterogeneous Catalysis

The overall objective of this project is to investigate the application of carbon nanomaterials as support in heterogeneous catalysis. In the study, carbon nanomaterials such as single-walled carbon nanotubes (SWNTs), multi-walled carbon nanotubes (MWNTs), carbon replica of zeolites and activated carbon are proposed as support in heterogeneous catalysis. The performance of carbon nanomaterials used will be studied and the comparison with activated carbon will be made to determine the effectiveness of the carbon nanomaterials as potential support in heterogeneous catalysis. The heterogeneous distribution of the nanoparticles that will be use such as nickel, iron and cobalt were evidenced by bulk and surface structural and compositional characterizations, that is, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, Fourier Transform Infrared (FTIR) and thermo gravimetric analysis (TGA). The significant of the application of carbon nanomaterials will be observed with the improvement in the catalytic efficiency of the chemical reaction. Various applications of carbon nanomaterials as support in heterogeneous catalysis can be seen in pharmaceutical, electrical, optical and mechanical applications