Halogen compound promoted Al.sub.2 O.sub.3 and/or SiO.sub.2 for

Halogen derivatives of ascorbic acid and D-araboascorbic acid an

Halogenated organoaluminum compounds and method of preparation

Halogenation process in the presence of cyanoquinone catalyst

Hals phosphonites as stabilizers

Heat resistant catalyst for the production of sulfuric acid for

Heating silica gel in inert atmosphere before activation

Heavy crude conversion

Heavy metal-manganese oxidation catalysts and process of produci

Hemoperfusion adsorbents

Heteroaryl substituted hydroxyphenyltriazine uv-absorbers

Heterocyclic benzoate ultraviolet stabilizers and their use in o

Heterogeneous anionic transition metal catalysts

Heterogeneous catalyst for oxidation of propylene into propylene

Heterogeneous catalyst on the basis of an organometallic complex

Heterogeneous catalyst supports

Heterogeneous catalytic hydrogenation

High activity amorphous silica-alumina catalyst

High activity catalyst for the polymerization of alpha-olefins

High apparent bulk density gamma alumina carrier and method of m