Abstract XPS, HREELS, ARUPS and Δo data show that furan chemisorbs non-dissociatively on Pd{111} at 175 K, the molecular plane being significantly tilted with respect to the surface normal. Bonding involves both the oxygen lone pair and significant π interaction with the substrate. The degree of decomposition that accompanies molecular desorption is a strong function of coverage: ∼40% of the adsorbate desorbs molecularly from the saturated monolayer. Decomposition occurs via decarbonylation to yield COa and Ha followed by desorption rate limited loss of H2 and CO. It seems probable that an adsorbed C3H3 species formed during this process undergoes subsequent stepwise dehydrogenation ultimately yielding H2 and Ca.