| 摘要 |
<p>1459780 Rare-earth-containing chrysotile EXXON RESEARCH & ENG CO 31 Dec 1973 [17 Jan 1973] 60292/73 Heading C1A [Also in Divisions B1 and C5] A hydrocarbon conversion catalyst comprises a synthetic chrysotile of the general formula where M and # are selected from monovalent and multivalent metal cations, of Groups Ia, Ib, IIa, IIb, IIIa, IIIb, IVb, Vb, VIb, VIIb and VIII of the Periodic Table of Elements, having an effective ionic radius ranging from 0À5 to 1À0 Š, RE is a rare earth metal, x is a number which expresses the atomic fraction of the metal # and ranges from 0 to 0À30, y is the atomic fraction of RE and ranges from 0À02 to 0À20, a is the valence of M and is an integer ranging from 1 to 7, b is the valence of # and is an integer ranging from 1 to 7, c is the valence of RE and is an integer ranging from 2 to 4, n is a number equal to the value defined by the ratio 6/[a(1- x-y)+bx+cy], and w is a number ranging from 0 to 4. Preferably M is Mg, Co or Ni, # is V, Cr, Mo, W, Mn, Re, Cu, Al, Zn or a Group VIII metal, and the rear earth is La. The products may be obtained by co-precipitating the metal oxides or hydroxides with hydrosilicate gel in an alkaline medium, and heating at 200- 350‹ C. to crystallize the product. With reducing pH of reaction, the products form as rods, thick-walled tubes, thin-walled tubes, curls and flakes.</p> |
