A fuel catalyst for improving combustion efficiency is provided that includes at least one hydride producing element, and at least one element of greater activity on the electrolytic scale than the hydride producing element and at least one element of lesser activity on the electrolytic scale than the hydride producing element. The hydride producing element preferably includes an element from at least one of a Group IV and Group V of the periodic table. The element of greater activity and the element of lesser activity preferably includes at least one of zinc, magnesium, aluminum, palladium, silver, copper and cerium. Preferred formulations of the catalyst element include: a) 20-60% wt antimony, 10-30% wt tin, 10-80% wt zinc and 1-5% wt silver; b) 40% wt antimony, 18% wt tin, 40% wt zinc and 2% wt silver; c) 20-60% wt antimony, 10-30% wt tin, 20-80% wt magnesium, 1-8% wt cerium and 0.1-1.0% wt palladium; d) 40% wt antimony, 25 % wt tin, 30% wt magnesium, 4.8% wt cerium and 0.2% wt palladium; and e) 25% wt antimony, 25% wt tin, 39% wt zinc and 11% wt aluminum.