Carbon dioxide and carbon monoxide undergo reactive chemisorption with cesium modified Cu(110) and Cu(110)-O surfaces and via the anionic intermediate CO2delta-(a) form a surface carbonate. The CO2delta-(a) species was characterised by VEELS and XPS at low temperature (80 K) and the surface carbonate at 295 K. For cesium modified Cu(110) surfaces chemisorption of carbon monoxide gives rise to electron energy loss peaks (nu(CO)) as low as 1450 cm-1 at 295 K.