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