Nickel-based oligomerization catalysts and method for oligomerizing light olefins using the same
In the present disclosure, a heterogeneous nickel-based oligomerization catalyst in which nickel in the form of single atom is loaded on an Al-mesoporous silicate support by ion exchange and a method for producing the same, and a method for oligomerizing light olefins, specifically C4 olefins using the catalyst are described.
1. A method for producing a heterogeneous oligomerization catalyst, the method comprising:
a) providing a Na-type Al-mesoporous silicate having a Si/Al atomic ratio in a range of 5 to 20 as a support, wherein aluminum (Al) forms acid sites on the mesoporous silicate and Na + ions are bound to the acid sites;
b) ion exchanging the Na + ions bound to the acid sites of the Na-type Al-mesoporous silicate with nickel ions using a nickel compound having an oxidation number of 2+, wherein the nickel ions are exchanged with the bound Na + ions, thereby being bound to the Al-mesoporous silicate; and
c) performing heat treatment of the Al-mesoporous silicate containing the exchanged nickel ion,
wherein nickel is supported on the support in a form of single atom of Ni and an amount of nickel supported is in a range of 0.1% to 10% by weight,
wherein an acid amount of the catalyst is less than 50 μmol/g, and
wherein a molar ratio of nickel (Ni)/aluminum (Al) is in a range of 0.3 to 1.
2. The method according to claim 1 , wherein at least 95% of Na + ions bound to acid sites of the Na-type Al-mesoporous silicate is exchanged with a nickel ion in the step b).
3. The method according to claim 1 , wherein the Al-mesoporous silicate is at least one selected from an AlMCM-based silicate or an AlSBA-based silicate.
4. The method according to claim 3 , wherein the Al-mesoporous silicate is at least one selected from AlMCM-48 or AlMCM-41.
5. The method according to claim 1 , wherein the Al-mesoporous silicate has a specific surface area (BET) of 200 to 1200 m 2 /g, a pore volume of 0.3 to 0.6 cc/g, and an average pore diameter of 18 to 40 Å.
6. The method according to claim 1 , wherein the nickel compound having an oxidation number of 2+is at least one selected from the group consisting of nickel nitrate, nickel sulfate, nickel phosphate, nickel halide, nickel carboxylate, nickel hydroxide, and nickel carbonate.
7. The method according to claim 1 , wherein a nickel concentration in an aqueous solution of the nickel compound having an oxidation number of 2+used during the ion exchange in the step b) is in a range of 0.01 to 10 M.
8. The method according to claim 7 , wherein ion exchange in the step b) is performed at 50° C. to 100° C.
9. The method according to claim 1 , wherein the step c) is carried out at 250° C. to 1000° C. in an oxygen-containing atmosphere.
10. The method according to claim 1 , wherein the step b) is carried out by directly ion exchanging the Na + ions of the Na-type Al-mesoporous silicate with nickel ions without passing through an exchange with ammonium ions.
11. The method according to claim 1 , wherein the oligomerization catalyst has a specific surface area (BET) of 150 to 1000 m 2 /g, a pore volume of 0.2 to 0.5 cc/g, and an average pore diameter of 10 to 35 Å.
12. The method according to claim 1 , wherein a particle size (diameter) of the oligomerization catalyst is in a range of 1 to 500 μm.
13. The method according to claim 1 , wherein the oligomerization catalyst substantially free of nickel oxide (NiO).