A liquid developed electrophotocopier wherein liquid carrier dispersant transferred to a copy sheet concomitantly with the developed image is catalytically oxidized to provide harmless gaseous oxidation products at temperatures sufficiently elevated to vaporize transferred carrier and to dry and fix the transferred image. The catalytic fixer-dryer is brought rapidly to operating temperature by injecting an atomized spray of carrier liquid. The carrier liquid has a low auto-oxidation temperature; and the fixer-dryer is operated above such temperature to ensure complete oxidation of carrier vapors even though the catalyst may have been largely rendered inactive.