Selective Oxidation Of Ethanol Research Articles

Non-uniform surface kinetics with two types of sites: the case of ethanol oxidation on molybdenum oxide

Temkin's theory of rates of catalytic reactions on non-uniform surfaces is extended to the MoO3-catalyzed oxidation of ethanol to acetaldehyde. Two types of sites are assumed to be present, an oxygen atom site that can be modeled with uniform properties and a metal atom site characterized by non-uniform properties both for ethanol chemisorption to an ethoxide intermediate and the conversion of this intermediate to acetaldehyde. The rate-limiting step is the cleavage of a C-H bond in the absorbed ethoxide intermediate. Non-uniform surface kinetics leads to a kinetic rate expression of the form $$v = kP_{C_2 H_5 OH}^{1 - m} P_{O_2 }^{(1 - m)/4} P_{H_2 O}^{ - (1 - m)/2} $$ . Such a rate expression, withm=0.14, is shown to provide a good fit to kinetic data for the selective oxidation of ethanol on a silica supported molybdenum oxide catalyst.

Promoting effects of Re and Cs on silver catalyst in ethylene epoxidation

Ethylene oxide is mainly produced from fossil-based ethylene. Only minor amounts of EO are based on renewable ethanol in a three-step process consisting of an ethanol dehydration step, an ethylene purification step, and an epoxidation step. We herein present a new one-step process for the selective oxidation of ethanol to ethylene oxide by a novel dual-layer concept without intermediate ethylene purification. Ethanol is dehydrated in one reactor on a first catalyst bed to ethylene which is subsequently epoxidized over a silver catalyst. The dual-layer arrangement allowed stable operation over more than 60 h and state-of-the-art conversions and selectivities were obtained.

Heterogeneous catalytic oxidation of ethanol: A new process for acetic acid

The selective oxidation of ethanol into acetic acid is carried out with a catalyst composed of tin oxide and molybdenum oxide. The best selectivity is obtained with 80% ethanol at 0.2 WHSV and 320°C, keeping the oxygen to alcohol mole ratio around 1∶1.