The present invention provides methods and apparatus for decomposing toxic compounds so that reaction by-products produced thereby are selectively reduced. A method generally comprises: introducing a carrier gas, having a toxic compound entrained therein, into a packed-bed of ferroelectric pellets; and polarizing the pellets to produce a plasma which decomposes the toxic compound. The pellets are coated with a catalyst selected to react with by-products of the decomposition of the toxic compound and thereby produce non-toxic compounds. An apparatus for decomposing toxic compounds and selectively reducing by-products, according to the present invention, comprises: a vessel having an internal passageway therethrough; a packed-bed of pellets coated with at least one catalyst; means for producing a plasma within the packed-bed of pellets; and carrier gas flow means in fluid communication with the internal passageway for causing a carrier gas entrained with toxic compounds to flow through the packed-bed of pellets. The present invention also discloses methods and apparatus wherein a pulsed corona reactor having a catalyst coating on a portion thereof is utilized to decompose toxic compounds.