A catalyst 3 comprising {TAIL ~ 4.0 wt % nickel} and {HEAD ~ 15.0 wt %} tungsten 
A catalyst 3 comprising { TAIL ~ 4.0 wt % nickel } and { HEAD ~ 15.0 wt % } tungsten
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH