Nickel-cobalt-based catalysts for co and no oxidation; their activation

Patent metadata

Field	Value
Publication number	US-2020282382-A1
Application number	US-201816644859-A
Country	US
Kind code	A1
Filing date	Sep 4, 2018
Priority date	Sep 5, 2017
Publication date	Sep 10, 2020
Grant date	—

Abstract

A catalyst obtainable by exsolving particles of Ni, Co and/or a mixture of Ni and Co from a perovskite metal oxide of formula (I) (M1aM2b)(COxNiyM3z)O3, wherein M1 and M2 are each independently an alkali earth metal or a rare earth metal, M3 is Ti or Cr, 0≤a≤1, 0≤b≤1, 0<a+b≤1, 0≤x<1, 0≤y<1, 0≤z<1, x+y+z=1 and where at least one of x and y>0. The invention includes methods of converting this catalyst into one or more catalytically active forms. The catalysts and the activated forms of same are useful in the catalysing CO oxidation and/or NO oxidation.

First claim

1 . A catalyst obtainable by exsolving particles of Ni, Co and/or mixtures of Ni and Co from a perovskite metal oxide of formula (I):
(M 1 a M 2 b )(Co x Ni y M 3 z )O 3   (I)
wherein M 1 and M 2 are each independently an alkali earth metal or a rare earth metal, M 3 is Ti or Cr, 0≤a≤1, 0≤b≤1, 0<a+b≤1, 0≤x<1, 0≤y<1, 0≤z<1, x+y+z=1, and at least one of x and y>0.

2 . A catalyst according to claim 1 , wherein the perovskite metal oxide of formula (I) is not La (1.6-2y) Ce (2y-0.7) Ni y Ti (1-y) O 3 .

3 . A catalyst according to claim 1 , wherein M 1 and M 2 are each independently chosen from (i) calcium, strontium, barium, lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, terbium, dysprosium and ytterbium; (ii) calcium, strontium, barium, lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, terbium, dysprosium and ytterbium; (iii) calcium, strontium, barium, lanthanum, cerium, praseodymium and neodymium; or (iv) lanthanum and cerium.

4 . A catalyst according to claim 1 , wherein: a>0, b=0, and M 1 is lanthanum; or a>0, b>0, M 1 is lanthanum and M 2 is chosen from cerium, praseodymium and neodymium; and wherein, x+y is from 0.3 to 0.5.

5 . A catalyst according to claim 1 , wherein (a+b)/(x+y+z)<1.

6 . A catalyst according to claim 1 , wherein x>0 and y>0, wherein formula (I) is La (1.2-x−2y) Ce (x+2y-0.4) Co x Ni y Ti (1-x-y) O 3 .

7 . A catalyst according to claim 1 , wherein y=0.

8 . A catalyst according to claim 1 , wherein x=0.

9 . A catalyst according to claim 1 , comprising exsolved Ni, Co or NiCo particles having an average particle diameter of from 2 to 50 nm, or 2 to 35 nm.

10 . A method of activating the catalyst according to claim 1 , comprising heating said catalyst from room temperature to a temperature of from 350 to 800° C. in the presence of CO and O 2 , wherein the mole ratio of O 2 :CO≥0.5.

11 . A method according to claim 10 , wherein the catalyst of formula (I) is La (1.2-x−2y) Ce (x+2y-0.4) Co x Ni y Ti (1-x-y) O 3 , or, wherein y=0.

12 . A method according to claim 10 , wherein x=0.

13 . A catalyst obtained/obtainable by the method of claim 11 .

14 . A catalyst obtained/obtainable by the method of claim 12 .

15 . A method of activating the catalyst according to claim 14 , comprising heating said catalyst at a temperature of from 400 to 600° C. in the presence of CO and O 2 , wherein the mole ratio of O 2 :CO<0.5.

16 . A method according to claim 11 , comprising a subsequent step of heating said catalyst at a temperature of from 400 to 600° C. in the presence of CO and O 2 , wherein the mole ratio of O 2 :CO<0.5.

17 . A catalyst obtained/obtainable by the method of claim 15 .

18 . A method of oxidizing CO and/or oxidizing NO comprising reacting CO and/or NO with oxygen in the presence of a catalyst according to claim 11 .

19 . A method of treating an exhaust gas from an internal combustion engine comprising passing said exhaust gas over a catalyst according to claim 11 .

Assignees

• Univ Court Univ St Andrews
• The Univ Of Newcastle Upon Tyne

Inventors

• Irvine John Thomas Sirr
• Neagu Dragos
• Metcalfe Ian
• Papaioannou Evangelos I

Classifications

• B01J35/70

  characterised by their crystalline properties, e.g. semi-crystalline (catalysts comprising carbon B01J21/18; molecular sieves B01J29/00) · CPC title

• B01J35/45

  Nanoparticles · CPC title

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J35/393

  Metal or metal oxide crystallite size · CPC title

• B01J35/733

  Perovskite-type · CPC title