The electrocatalytic behaviour of tellurium-modified Pt(lll) electrodes for the oxidation of formic acid was investigated. For the direct oxidation of formic acid, an enhancement of catalysis was observed, yielding a maximum formic acid oxidation current for a tellurium coverage of 0.24. In poison formation experiments, the tellurium adsorbed on the surface inhibited poison formation and accumulation by an electronic effect. A comparison was made with other s(2)p(n) adatoms. It was found that the elements which have a lower work function than platinum inhibit poison formation through a long-range electronic effect when they are adsorbed on the Pt(111) electrode.