Abstract: Disclosed are a method for preparing a noble metal hydrogenation catalyst comprising preparing a carrier from a molecular sieve having a 10-member ring structure and/or an amorphous porous material; preparing a noble metal impregnation solution; and preparing noble metal impregnation solutions in a concentration gradient ranging from 0.05 to 5.0 wt % with deionized water, and sequentially impregnating the carrier with the impregnation solutions from low to high concentrations during the carrier impregnation process, or preparing a noble metal impregnation solution at a low concentration ranging from 0.05 to 0.5 wt % and impregnating the carrier by gradually increasing the concentration of the noble metal impregnation solution to 2.0 to 5.0 wt % in the impregnation process, followed by homogenization, drying, and calcination, as well as a noble metal hydrogenation catalyst, use thereof, and a method for preparing lubricant base oil.

Abstract: Disclosed are a method for preparing a noble metal hydrogenation catalyst comprising preparing a carrier from a molecular sieve having a 10-member ring structure and/or an amorphous porous material; preparing a noble metal impregnation solution from one or more of compounds of noble metals Pt, Pd, Ru, Rh, Re, and Ir and deionized water or an acid solution; and preparing noble metal impregnation solutions in a concentration gradient ranging from 0.05 to 5.0 wt % with deionized water, and sequentially impregnating the carrier with the impregnation solutions from low to high concentrations during the carrier impregnation process, or preparing a noble metal impregnation solution at a low concentration ranging from 0.05 to 0.5 wt % and impregnating the carrier by gradually increasing the concentration of the noble metal impregnation solution to 2.0 to 5.

Abstract: A supercritical carbon dioxide-assisted solid-phase grafting modification method for polypropylene, comprises swelling polypropylene for 0.5 to 10 hours in supercritical carbon dioxide having dissolved vinyl monomer and an initiator, then slowly relieving the pressure; moving the polypropylene that has undergone the swelling process into a reaction kettle, and adding xylene as an interface agent, the mass of xylene being 1% of the polypropylene; increasing the temperature to between 65° C. and 165° C. under normal pressure, and reacting 1 to 10 hours to obtain modified polypropylene; the swelling permeation temperature during the swelling process is from 31° C. to 60° C., the swelling pressure is from 7.5 to 12 MPa; the initiator is an azo compound or a peroxide. In the present method, the grafting rate reaches 5.4%, the thermal property, polarity, and mechanical property all improve substantially, and hydrophilic property is substantially enhanced.