{HEAD ~ Preferred catalyst} comprises potassium antimonate together with {TAIL ~ potassium sulfate} and minor amounts of zinc sulfate and cupric sulfate  
{ HEAD ~ Preferred catalyst } comprises potassium antimonate together with { TAIL ~ potassium sulfate } and minor amounts of zinc sulfate and cupric sulfate
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH