1997 年 18 巻 8 号 p. 478-484
Formate species synthesized on Cu(111) by the hydrogenation of CO2 at atmospheric pressure in a reactor was observed by UHV-STM. The ordered structure of the formate species changed in the order of p(2×4), c(2×8), (7×7), p(2×3), (5×5) and c(2×4) with increasing coverage, indicating that various ordered structures appeared corresponding to a small change in the formate coverage. The coverage of formate species in the c(2×4) structure corresponded to ΘHCOO= 0.25, which was in good agreement with a saturation coverage measured by XPS at the same reaction condition; thus, particles seen in the STM images indicate each formate species. Further, at a low formate coverage (ΘHCOO= 0.02), formate chains were observed.