Pore-diameter-adjustable alumina carrier and preparation method thereof

The invention discloses a pore-diameter-adjustable alumina carrier and a preparation method thereof. The particle inner pore diameter of the alumina carrier is gradually increased from the center to the outer surface along the radial direction; the pore diameter at the particle center of the alumina carrier is 1-8 nm smaller than the average pore diameter at a 50%-particle-diameter position; the average pore diameter at the 50%-particle-diameter position is about 1-5 nm smaller than that at a 80%-particle-diameter position; the average pore diameter at the 80%-particle-diameter position is about 1-5 nm smaller than that of the outer surfaces of the particles; the water absorption rate is 65%-75%, the specific surface area is 120-220 m /g, the pore volume is 0.6-0.8 mL/g, and the pore diameter distribution is 10-20 nm. The pore diameters are in a horn-shaped distribution state that the pore diameters are gradually increased from the particle center to the outer surface in the radial direction, and compared wit