Athabasca coker feed bitumen has been treated with halide catalysts under a continuous flow of H2 in a 15-mL microautoclave. The H2 was bubbled through the liquid by using a microporous steel grid. ZnCl2, CuCl, and ZnCl2/CuCl mixtures, with and without tetralin, were used as catalysts. The experimental conditions were as follows: 13.8-MPa operating pressure, 1 L/min H2 flow rate, 425–450 °C, and 30-min reaction time. ZnCl2 has been found effective for converting asphaltenes into maltenes while lowering the coke formation with respect to the uncatalyzed reaction. The addition of tetralin to the reaction mixture minimized coke and gas formation.