A "catalytic" heater uses a catalyst (usually platinum) to allow fuel
(usually propane, gasoline or natural gas) to combust with oxygen at a
lower than normal temperature without flame. Thus a "12 volt catalytic
heater" which doesn't use propane or some other fuel is highly unlikely.
However, the vented catalytic heaters do require about 1/2 amp of 12v to
run their control units and vent fans. 

IMO, 1200 btu would accomplish very little. My heater is 6000 btu, and 
that seems about right.

The huge advantage of vented catalytics is 1) no danger of carbon 
monoxide 2) No need to leave a window open 3) No moisture condensation 
inside and resulting corrosion.

--David Garth