Provided is a method capable of industrially efficiently producing acetic acid yielding a good potassium permanganate test result, without costing much. In the acetic acid production method, (1) by-produced acetaldehyde is industrially advantageously removed from a process stream, and (2) a crotonaldehyde concentration in an acetic acid stream from a light ends column is controlled to a specific level or lower, and/or a reflux ratio at a second distillation column is controlled to 0.1 or more. In addition, (3) the method includes the step of subjecting at least one of an aqueous phase and an organic phase of a light ends column overhead condensate to distillation in a crotonaldehyde-removing column; the light ends column is operated at a reflux ratio of 2 or more (when the aqueous phase is refluxed); and the crotonaldehyde-removing column is operated so as to meet a specific condition(s).

A precious metal-supported eggshell catalyst with a preparation method and an application are provided. The precious metal-supported eggshell catalyst includes a carrier, a precious metal and a promoter. As an active component, the precious metal and the promoter are evenly distributed on surface of the carrier, wherein the promoter includes one or more than two of a precious metal, an alkaline earth metal, a transition metal lanthanide series metal, an actinium series metal and/or a metal oxide thereof. With a highly utilization of the precious metal, the precious metal-supported eggshell catalyst showed high conversion, good selectivity and excellent stability, and the precious metal-supported eggshell catalyst is used more than 300 hours with no obvious loss of activity in preparing 1,3-propanediol through hydrogenation of 3-hydroxypropionaldehyde aqueous solution. Furthermore, with large particles the precious metal-supported eggshell catalyst is easily separated from reaction products.

Methods for producing a carbon-free, PGM-free support for PGM catalyst. The catalytic material comprises PGM metals disposed on a carbon-free support which is catalytic but free of PGM.

Methods of converting ethane to ethylene at relatively low temperatures are described. IrO.sub.2-based catalysts are used in the conversion. Methods of converting a base gas to a first gas by exposing the base gas to an IrO.sub.2-based catalyst and forming the first gas are described. The base gas can be an alkane. The first gas can include an alkene, an alkyne, an alcohol, an aldehyde, or combinations thereof.

Ethylene glycol is prepared from a carbohydrate source in a process,

wherein hydrogen, the carbohydrate source, a liquid diluent and a catalyst system are introduced as reactants into a reaction zone;

wherein the catalyst system comprises a tungsten compound and ruthenium as hydrogenolysis metal and further at least one promoter metal, selected from transition and post-transition metals;

wherein the carbohydrate source is reacted with hydrogen in the presence of the catalyst system to yield a product mixture comprising ethylene glycol and butylene glycol.

Butylene glycol may selectively be removed from the product mixture by azeotropic distillation using an entraining agent.

A nitrous oxide (N.sub.2O) removal catalyst composite is provided, comprising a N.sub.2O removal catalytic material on a substrate, the catalytic material comprising a rhodium (Rh) component supported on a ceria-based support, wherein the catalyst composite has a H.sub.2-consumption peak of about 100° C. or less as measured by hydrogen temperature-programmed reduction (H.sub.2-TPR). Methods of making and using the same are also provided.

A method produces acetic acid and includes a reaction step, a first purification step, a second purification step, and a third purification step. In the reaction step, a material mixture including methanol, carbon monoxide, a catalyst, and an iodide is subjected to a methanol carbonylation reaction in a reactor (1) to form acetic acid. In the first purification step, a crude acetic acid stream including acetic acid formed in the reaction step is subjected to distillation in a distillation column (3) to give a first acetic acid stream enriched with acetic acid. In the second purification step, the first acetic acid stream is subjected to distillation in a distillation column (5) to give a second acetic acid stream further enriched with acetic acid. In the third purification step, an acetic acid stream is subjected to purification in an additional purification unit (e.g., a distillation column (6)) while controlling the corrosive iodine concentration in the acetic acid stream passing through the unit to 100 ppm or less, to give a third acetic acid stream still further enriched with acetic acid. The method for producing acetic acid is suitable for restraining corrosion of the acetic acid production equipment.

The present invention relates to a methane combustion catalyst including platinum and iridium supported on a tin oxide carrier for combusting methane in a combustion exhaust gas containing sulfur oxide. In the methane combustion catalyst, a ratio R.sub.TO of platinum oxides to metal platinum is 8.00 or more, wherein the ratio R.sub.TO is based on existence percentages of the metal platinum (Pt) and the platinum oxides (PtO and PtO.sub.2) obtained from a platinum 4f spectrum analyzed and measured by X-ray photoelectron spectroscopy (XPS) and calculated in accordance with the following expression. In the following expression, R.sub.Pt is an existence percentage of the metal platinum (Pt), R.sub.Pto is an existence percentage of PtO, and R.sub.Pto2 is an existence percentage of PtO.sub.2.

R.sub.TO=(R.sub.PtO+R.sub.PtO2)/R.sub.Pt  [Expression 1]

Provided herein is a device for removing residual hydrogen peroxide or hydrazine from an effluent gas stream which includes a metal oxide scrubber material configured to react with residual process gases under increased temperatures. Also provided are systems and methods of using the same.

A catalyst comprising particles of iridium oxide and a metal oxide (M oxide), wherein the metal oxide is selected from the group consisting of a Group 4 metal oxide, a Group 5 metal oxide, a Group 7 metal oxide and antimony oxide, wherein the catalyst is prepared by subjecting a precursor mixture to flame spray pyrolysis, wherein the precursor mixture comprises a solvent, an iridium oxide precursor and a metal oxide precursor is disclosed. The catalyst has particular use in catalysing the oxygen evolution reaction.