Abstract A series of silica gel immobilized lanthanum catalysts were prepared for the atom- economy synthesis of N-substituted carbamates from urea derivatives and dimethyl carbonate. The La/SiO 2 catalysts with lanthanum loadings varied from 1.3 wt% to 8.5 wt% were characterized by AES, BET, XRD, TEM, FT-IR, XPS and TPD. According to the characterization, lanthanum species with particle sizes of 5–10 nm on the surface of silica ...
