Provided is an exhaust gas purification catalyst that suppresses phosphorus poisoning and improves long-term durability. The exhaust gas purification catalyst includes a phosphorus collection layer and a catalyst layer containing at least one precious metal element M.sup.p selected from the group consisting of Pt, Pd, and Rh, wherein the phosphorus collection layer is arranged on the upper layer side and/or the upstream side with respect to the catalyst layer; the phosphorus collection layer contains a composite oxide containing Al and an alkaline earth metal element M.sup.a that includes Mg and that may include at least one selected from the group consisting of Ca, Sr, and Ba, and having a cubic spinel structure belonging to the space group Fd-3m; the composite oxide has a M.sup.a/Al molar ratio in a range of 0.02 or more and 0.60 or less; and the composite oxide has a peak derived from the cubic spinel structure belonging to the space group Fd-3m of the composite oxide between a diffraction angle 2x.sub.M.sup.a.sub.O that is a position of a peak derived from an alkaline earth metal oxide M.sup.aO and a diffraction angle 2x.sub.Al2O3 that is a position of a peak derived from an aluminum oxide Al.sub.2O.sub.3 in an X-ray diffraction spectrum.

In a spherical titanium silicalite catalyst and a preparation method therefor, the spherical titanium silicalite catalyst has the following composition: xTiO.sub.2.Math.(1x)SiO.sub.2/yMPO.sub.4, wherein x is equal to 0.0005-0.04, y is equal to 0.005-0.20, M is a metal element selected from alkaline earth metals, transition metals or combinations of two or more thereof. The spherical titanium silicalite catalyst is prepared by the following method: (i) providing titanium silicalite raw powder with the composition of xTiO.sub.2.Math.(1x)SiO.sub.2, wherein x is equal to 0.0005-0.04, and y is equal to 0.005-0.20; (ii) mixing silica sol, an organic template agent and phosphate in proportion to obtain an adhesive; and (iii) mixing the adhesive with the titanium silicalite raw powder, and carrying out spray-drying molding and firing to obtain the titanium silicalite catalyst.

A photocatalytic liquid is disclosed. The photocatalytic liquid includes a noble metal nanoparticle being in a weight percentage of 0.01-0.2 wt. % of the photocatalytic liquid, and including a silver nanoparticle; a photocatalytic nanomaterial being in a weight percentage of 0.01-25 wt. % of the photocatalytic liquid, and including at least one of a titanium nanoparticle and a tungsten trioxide nanoparticle; a dispersant in a weight percentage of 0.01-5 wt. % of the photocatalytic liquid; and a balance of a solvent.

A photocatalytic liquid is disclosed. The photocatalytic liquid includes a noble metal nanoparticle being in a weight percentage of 0.01-0.2 wt. % of the photocatalytic liquid, and including a silver nanoparticle; a photocatalytic nanomaterial being in a weight percentage of 0.01-25 wt. % of the photocatalytic liquid, and including at least one of a titanium nanoparticle and a tungsten trioxide nanoparticle; a dispersant in a weight percentage of 0.01-5 wt. % of the photocatalytic liquid; and a balance of a solvent.