Catalyst preparation utilizing metal nitrates and nitrogen oxide scavenger
AssigneeMonsanto Company
InventorsWesley B. Argo, James W. Edwards, Albert P. Little, William M. Lumb
Life of this patent
Estimating the term…
Abstract
Provisions are taken to counter nitrogen oxide fumes produced in catalyst preparation involving metal nitrate decomposition, as by including urea or another scavenger, or by delaying calcining until used as catalyst in treating auto exhaust.
Claims13
In a method of preparing a catalyst by forming a mixture of a metal nitrate and catalyst support and heating the mixture to decompose the metal nitrate, the improvement of adding a nitrogen oxide scavenger to the mixture, before heating, in an amount sufficient to scavenge the nitrogen oxide produced upon decomposition of the metal nitrate, the said scavenger being selected from the group consisting of lower carboxylic acid amides containing no more than six carbon atoms and urea-formaldehyde resin.
A catalyst precursor composition consisting essentially of an alumina support, palladium and chromium nitrates, and a lower aliphatic carboxylic acid amide containing no more than six carbon atoms in an amount sufficient to scavenge the nitrogen oxide produced upon decomposition of the nitrates, and the nitrate amounts are such that palladium, calculated as metal, is in the range of 0.001 to 0.5 weight parts, and chromium, calculated as metal, 0.1 to 10 weight parts, both per 100 weight parts support.
A catalyst precursor composition consisting essentially of an alumina support, palladium and chromium nitrates, and urea-formaldehyde resin in an amount sufficient to scavenge the nitrogen oxide produced upon decomposition of the nitrates, and the nitrate amounts are such that palladium, calculated as metal, is in the range of 0.001 to 0.5 weight parts, and chromium, calculated as metal, 0.1 to 10 weight parts, both per 100 weight parts support.
Dependencies are inferred from the claim text.