Porous formed body and production method thereof, α-olefin dimerization catalyst and production method thereof, and method of producing α-olefin dimer

A method of producing a porous formed body (Y), the method comprising:

• a step of supporting an alkali metal carbonate or an alkali metal bicarbonate on a porous formed body (X) that satisfies the following requirements (x-1) to (x-4), in a range of from 1 part by mass to 230 parts by mass of the alkali metal carbonate or the alkali metal bicarbonate with respect to 100 parts by mass of the porous formed body (X), thereby obtaining a supported material;
• and
• a step of heat treating the supported material at 100° C. to 500° C. to obtain a porous formed body (Y):
• wherein the porous formed body (Y) has a volume of pores with a pore diameter in a range of from 0.01 μm to 100 μm of from 0.15 mL/g to 0.80 mL/g;
• requirement (x-1):
• a volume of pores with a pore diameter in a range of from 0.01 μm to 100 μm is from 0.10 mL/g to 1.00 mL/g;
• requirement (x-2):
• a median pore diameter of pores with a pore diameter in a range of from 0.01 μm to 100 μm is from more than 0.01 μm to 10.0 μm;
• requirement (x-3):
• a crushing strength is from 0.7 kgf to 15.0 kgf;
• and
• requirement (x-4):
• the porous formed body (X) contains at least one compound selected from the group consisting of an oxide of a metal, an oxide of a rare earth element, a complex oxide of a metal and a rare earth element, zeolite, activated carbon, and SiC.