The Catalytic Decomposition of Methanol into Syngas for Use as an Automotive Fuel

A l t h o u g h m e t h a n o l i s t h o u g h t t o b e a n e x c e l l e n t a u t o m o t i v e f u e l , i t h a s a smaller v o l u m e t r i c f u e l v a l u e t h a n g a s o l i n e . T h e c a t a l y t i c d e c o m p o s i t i o n o f m e t h a n o l i n t o s y n g a s , p r i o r t o i t s c o m b u s t i o n i n t h e e n g i n e , i m p r o v e s i t s f u e l v a l u e by a p p r o x i m a t e l y 1 4 % . P a l l a d i u m a n d p l a t i n u m o n m o d i f i e d a l u m i n a s u p p o r t s d e m o n s t r a t e t h e n e c e s s a r y q u a l i t i e s f o r t h i s p r o c e s s . T h e c a t a l y t i c a c t i v i t y a n d t h e r m a l s t a b i l i t y o f p a l l a d i u m is s t r o n g l y a f f e c t e d by t h e n a t u r e o f t h e c a t a l y s t s u p p o r t u s e d . A gamma-a lumina s u p p o r t was m o d i f i e d w i t h t h e o x i d e s o f L i , Mg, C s , a n d La . T h e e f f e c t o f t h e m o d i f i e d s u p p o r t on t h e a c t i v i t y , s e l e c t i v i t y , a n d t h e r m a l s t a b i l i t y o f t h e p a l l a d i u m m e t a l was s t u d i e d d u r i n g e x p o s u r e t o a t h e r m a l c y c l e o f 300, 500, a n d 30OoC. T h e p r o f o u n d d i f f e r e n c e i n c a t a l y s t b e h a v i o r may b e d u e t o s t r o n g m e t a l s u p p o r t i n t e r a c t i o n s , t o v a r i a t i o n s i n metal d i s p e r s i o n , or t o c h e m i c a l a l t e r a t i o n o f t h e p a l l a d i u m . I n o r d e r t o d e t e r m i n e t h e c h e m i c a l s t a t e o f t h e p a l l a d i u m metal a n d t h e m o d i f i e d s u p p o r t b e f o r e a n d a f t e r t e s t i n g , t h e c a t a l y s t s were c h a r a c t e r i z e d b y TPD, X R D , XPS, a n d v o l u m e t r i c c h e m i s o r p t i o n t e c h n i q u e s .