In Situ IR Characterization of CO Interacting with Rh Nanoparticles Obtained by Calcination and Reduction of Hydrotalcite-Type Precursors

Table 2

FT-IR data of CO interaction at r.t. and Rh particle size evaluated by TEM analysis.

Sample	νRh^0CO; (cm^−1)	νRh^I(CO)2; (cm^−1)	ν(Rh2)CO; (cm^−1)	CO; disprop.^c	dparticles; (nm)
Rh/HTCarb_750	2050	2096^a	—	YES	1.8
Rh/HTCarb_950	2060	2093, 2032^b	1915	small extent	1.4
Rh/HTSil_750	2048	—	—	NO	1.1

^a The asymmetric mode is overlapped with the monocarbonyl stretch.
^bLower relative amount with respect to Rh/HTCarb_750.
^cCO disproportionation as revealed by the formation of carbonate-like species.