Double peroxide treatment of oxidative dehydrogenation catalyst

Patent metadata

Field	Value
Publication number	US-10406517-B2
Application number	US-201715839947-A
Country	US
Kind code	B2
Filing date	Dec 13, 2017
Priority date	Jan 6, 2017
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

Oxidative dehydrogenation catalysts comprising MoVNbTeO having improved consistency of composition and a 25% conversion of ethylene at less than 420° C. and a selectivity to ethylene above 95% are prepared by treating the catalyst precursor with H2O2 in an amount equivalent to 0.30-2.8 mL H2O2 of a 30% solution per gram of catalyst precursor prior to calcining and treating the resulting catalyst with the equivalent amount of peroxide after calcining.

First claim

What is claimed is:

1. A method to improve the consistency of an oxidative dehydrogenation catalyst of the empirical formula
(measured by PIXE): Mo 1.0 V 0.25-0.38 Te 0.10-0.16 Nb 0.15-0.19 O d
where d is a number to satisfy the valence of the oxide;
the method comprising preparing the oxidative dehydration catalyst by:
i) forming an aqueous solution of ammonium heptamolybdate (tetrahydrate) and telluric acid at a temperature from 30° C. to 85° C. and adjusting the pH of the solution to from 6.5 to 8.5, with a nitrogen-containing base to form soluble salts of the metals;
ii) preparing an aqueous solution of vanadyl sulphate at a temperature from room temperature to 80° C.;
iii) mixing the solutions from steps i) and ii) together;
iv) slowly (dropwise) adding a solution of niobium monoxide oxalate (NbO(C 2 O 4 H) 3 ) to the solution of step iii) to form a slurry;
v) heating the resulting slurry in an autoclave under an inert atmosphere at a temperature from 150° C. to 190° C. for not less than 10 hours;
vi) filtering and washing with deionized water, and drying the washed solid from step v) for a time from 4 to 10 hours at a temperature from 70 to 100° C. to form a dried catalyst precursor;
vii) treating said dried catalyst precursor from step vi) with the equivalent of from 0.3-2.8 mL of a 30% w/w solution of H 2 O 2 per gram of said dried catalyst precursor for a time from 5 minutes to 10 hours at a temperature from 20 to 80° C.;
viii) calcining the resulting catalyst precursor in an inert atmosphere at a temperature from 200° C. to 600° C. for a time from 1 to 20 hours to form a calcined catalyst;
ix) recovering the calcined catalyst from step viii) and treating it with the equivalent of from 0.3-2.8 mL of a 30% w/w solution of H 2 O 2 per gram of calcined catalyst for a time from 5 minutes to 10 hours at a temperature from 20 to 80° C.; and
x) recovering the treated calcined catalyst to provide the oxidative dehydration catalyst.

2. The method according to claim 1 , wherein in the catalyst the molar ratio of Mo:V is from 1:0.26 to 1:0.38.

3. The method according to claim 2 , wherein in the catalyst the molar ratio of Mo:Te is greater than 1:0.11 and less than 1:0.15.

4. The method according to claim 3 , wherein in the catalyst the molar ratio of Mo:Te is from 1:0.11 to 1:0.13.

5. The method according to claim 1 , wherein the catalyst has a bulk density from 1.20 to 1.53 g/cc.

6. The method according to claim 1 , wherein in the crystalline phase of the catalyst the amount of the phase having the formula (TeO) 0.39 (Mo 3.52 V 1.06 Nb 0.42 )O 14 is above 75 wt % of the measured crystalline phase.

7. The method according to claim 1 , wherein the catalyst has an XRD diffraction pattern (reflections data) where the reflection at 21.81° (±−0.4°) 2θ is 1-6% relative peak height of the reference reflection at 22.29° (±0.4°) 2θ.

8. The method according to claim 1 , wherein the catalyst has an XRD pattern where the reflection at 22.29° (±0.4°) 2θ has a full width at half maximum (FWHM) less than 0.185° 2θ.

9. The method according to claim 1 , wherein the surface of the autoclave is selected from the group consisting of stainless steel, silica, glass (PYREX), alumina coating and polytetrafluoroethylene.

10. The method according to claim 1 , wherein the autoclave contains particulates (irregular such as flakes, granules, globules, filaments etc. or regular such as spheres, elliptical, rods, rectangular prisms (both right and non-right), pentagonal prisms, pyramids, etc.) of stainless steel, silica, alumina and polytetrafluoroethylene seeded with the above catalyst.

11. The method according to claim 1 , the autoclave is internally coated with a fully fluorinated ethylene propylene polymer reactor seeded with the catalyst.

Assignees

• Nova Chem Int Sa

Inventors

• Simanzhenkov Vasily
• Gao Xiaoliang
• Sullivan David Jeffrey
• Drag Hanna
• Barnes Marie

Classifications

• C07C2527/057

  Selenium or tellurium; Compounds thereof · CPC title

• C07C2523/22

  Vanadium · CPC title

• C07C2523/20

  Vanadium, niobium or tantalum · CPC title

• B01J37/031

  Precipitation · CPC title

• B01J37/0009

  Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst · CPC title