A process for treating organic compounds includes providing a composition which includes a substantially mesoporous structure of refractory oxide containing at least 97% by volume of pores having a pore size ranging from about 15 .ANG. to about 30 .ANG. and having a micropore volume of at least about 0.01 cc/g, wherein the mesoporous structure has incorporated therewith at least about 0.02% by weight of at least one catalytically and/or chemically active heteroatom selected from the group consisting of Al, Ti, V, Cr, Zn, Fe, Sn, Mo, Ga, Ni, Co, In, Zr, Mn, Cu, Mg, Pd, Pt and W, and the catalyst has an X-ray diffraction pattern with one peak at 0.3.degree. to about 3.5.degree. at 2 theta (.theta.). The catalyst is contacted with an organic feed under reaction conditions wherein the treating process is selected from alkylation, acylation, oligomerization, selective oxidation, hydrotreating, isomerization, demetalation, catalytic dewaxing, hydroxylation, hydrogenation, ammoximation, isomerization, dehydrogenation, cracking and adsorption.