Abstract: A zeolite catalyst suitable for use in shape-selective hydrocarbon conversion processes. The catalyst is modified by incorporation therein of a hydrogenation-dehydrogenation functional metal, followed by gradient selectivation with an organosilicon compound under conversion conditions, wherein the gradient selectivation conditions are characterized by a progressive temperature gradient. The use of a progressive temperature gradient during the in situ selectivation procedure unexpectedly yields a catalyst in which the hydrogenation-dehydrogenation function is stabilized, thereby enabling long duration hydrocarbon conversion processes with low by-product make.

Abstract: An improved PVOH-based coating solution for application to a polymeric substrate. The coating solution includes poly(vinyl alcohol), a formaldehyde-containing crosslinking agent and a crosslinking-promoting acid catalyst which lowers the pH of the solution to about 3.5 or less and, preferably, to about 3 or less. The coating solution exhibits improved viscosity stability, particularly with the addition of a second acid catalyst. The coating solution also provides improved crosslinking and oxygen barrier characteristics upon drying.