One aspect of the invention relates to a catalyst composite containing an extruded catalyst support containing an extruded activated carbonaceous material having specifically a defined pore structure. For example, the extruded activated carbonaceous material may have pores wherein at least about 40% of total Hg porosity occurs in pores having a diameter of about 200 .ANG. and larger. Alternatively the extruded activated carbonaceous material may have a first set of pores having a pore diameter of at least about 40 .ANG. and at most about 100 .ANG. with a porosity of at least about 0.15 cc/g, and a second set of pores having a pore diameter of at least about 5,000 .ANG. and at most about 20,000 .ANG. with a porosity of at least about 0.3 cc/g.