Metal catalyst composition

摘要

Embodiments include metal catalyst compositions and methods of forming metal catalyst compositions. A metal catalyst composition can be formed by (a) contacting a supported metal catalyst surface with a ligand-containing alumina precursor for a predetermined contact time to form an intermediate layer having a plurality of aluminum moieties that chemically bond to the supported metal catalyst surface, optionally, contacting the intermediate layer of aluminum moieties with an inert gas for a predetermined intermediate stripping time to remove unreacted ligand-containing alumina precursors, (b) reacting the aluminum moieties with an oxidation reagent for a predetermined reaction time to convert at least a portion of the ligands to hydroxyl groups thereby forming a layer of the alumina over-coat on the supported metal catalyst surface or a previously formed layer of the alumina over-coat, (c) contacting the layer of the alumina over-coat formed in step (b) with an inert gas for a predetermined stripping time to remove unreacted oxidation reagents, replicating the sequential steps (a-c) to form an additional layer of the alumina over-coat, and (d) activating the alumina over-coat, after forming a final layer of the alumina over-coat, to form a plurality of pores therein.

主权项

1. A method of forming a metal catalyst composition, comprising:
performing a plurality of atomic layer deposition cycles to form metal oxide over-coat on a supported metal catalyst, where one or more of the atomic layer deposition cycles include sequential steps:
(a) contacting a supported metal catalyst surface with a ligand-containing metal oxide precursor for a predetermined contact time to form an intermediate layer having a plurality of metal moieties that chemically bond to the supported metal catalyst surface;(b) reacting the metal moieties with water for a predetermined reaction time to convert at least a portion of the ligands to hydroxyl groups thereby forming a layer of the metal oxide, metal hydroxide, or metal oxyhydroxide over-coat on the supported metal catalyst surface or a previously formed layer of the metal oxide, metal hydroxide, or metal oxyhydroxide over-coat;(c) prior to replicating sequential steps (a) and (b) to form an additional layer of the metal oxide over-coat, contacting the layer of the metal oxide, hydroxide, oxyhydroxide over-coat formed in step b) with an inert gas for a predetermined final stripping time to remove unreacted water; and(d) activating the metal oxide, metal hydroxide, metal oxyhydroxide over-coat, after forming a final layer of the said over-coat, in the presence of a non-reducing gas at a temperature within a range from 500° C. to 800° C. for 60 minutes to 10 hours to form a layer of metal oxide having a thickness of from 1 nanometer to 100 nanometers with a plurality of pores therein, where at least 80 percent of the plurality of pores have a diameter within a range of 0.3 nanometers to 5 nanometers, and where the metal catalyst composition reduces an amount of coke formed during a dehydrogenation or an oxidative dehydrogenation reaction, as compared to same supported metal catalysts without the metal oxide over-coat.