_~TRQpUCTIONGeneral trends between geometricalelectronic properties and electrocatalyst activity have been the subject of many papers and review articles (1-4). In fact, much of the interest may be traced to the "volcano relationship" between the logarithm of the reaction rate and the free energy of adsorption,/kG~d ~, derived from electrochemical ~rInciples for the hydrogen evolution reaction (5,6). Assuming that/kS d remains constant, many workers hav~ ~bserved the "volcano type" behavior between the logarithm of the reaction rate and various quantities which may be rationalized to be proportional to/kH ~ . This assumption should . s * Electrochemacal Society Active Member.

No abstract

Thh~w.(~~ar.rrsccopntofmrilt~trJr~ysag&thsUaitsdst.h C&wmomt. N d t h a r t h e U a i t s d S t r~O o v o r m n s n t a a r . n y~M s 8 o r~y a f t b s i r s m p l o~m a k a 8 a~r u r m t y ,~o t i m p l i s d , o r -u r y k g . l l t b i l i t r a m r p o a s ib i t i t y f o r t h r r~Results of. further studies conducted at Giner , Inc. identified Cu and CuO/ZnO to be especially attractive sorbents and the use of steam-air to be efficient for regeneration of the spent sorbent. Further optimization has established highly dispersed CuO on zeolite, highly dispersed [CuO + ZnOl on zeolite, and a coprecipitated CuO/ZnO as the three most promising sorbents for efficient utilization of the theoretical desulfurizationcapacity. Based on engineering considerations, such a s desulfurization c a p a c i t y i n per weight o r volume of sorbents, a coprecipitated C~O / Z~O was , .s e l e c t e d f o r f u r t h e r study. A s t r u c t u r a l reorganization mechanism., unique t o mixed oxides, was identified: the creation .of r e l a t i v e l y f i n e c r y s t a l l i t e s of t h e sulfided components (Cu2S and ZnS) t o counteract t h e l o s s of surface area due t o s i n t e r i n g during regeneration. Studies w i t h 9 t o 26% water vapor i n simulated c o a l gases show t h a t s u l f u r l e v e l s below 1 ppm can be achieved i n t h e temperature range of 500' t o 650'~. The a b i l i t y of CuO/znO t o remove COS, CS2 and CHjSH a t these conditions has been demonstrated in t h i s study. Also a previously proposed pore-plugging model was f u r t h e r developed with good success for data treatment of both packed bed and fluidized-bed reactors. Ananth of Indian I n s t i t u t e of Technology, Madras (Visiting Professor a tPrinceton Ilniversity) provided expert qu.idance i n mathematical modelin@.

No abstract