Table 2. Comparison of TiO₂ Catalysts for the Reaction of Phenoxyacetic Acid with Acrylamide.

entry	catalyst	yield of adduct (%)a
1	P25	47 (82b)
2	PC500c	39
3	sol–gel tubed	73 (68e)
4	Photospheresf	9

^aNMR yields.

^bIsolated yield from 5:1 acid/acrylamide irradiated for 62 h.

^cMillenium PC500 (anatase, surface area ∼300 m² g^–1, particle size 5–10 nm).

^dSchlenk tubes coated internally with P25 by a sol–gel process.

^eYield of the isolated product.

^fHollow glass spheres (mean diameter 45 μm, density 0.22 g/mL) coated with TiO₂, from Microsphere Technology.