The CO chemisorption on some active sites of Pd clusters : A DFT study
Abstract The CO adsorption on Pd, Pd 2 and Pd 4 small clusters was studied using density functional methods; the theoretical results obtained here were compared with experimental vibration frequencies of CO adsorbed on supported Pd-nanoparticles. The results indicate that the CO adsorption over Pd 2 and Pd 4 clusters give CO vibration frequencies values closed to the experiment values. Also, the theoretical results for the threefold hollow sites were compared with other nanoclusters, with n >50 atoms, where the Pd 4 cluster also give values closed to the experiment. According with the results, two and four atoms small clusters could be used to model the active interaction sites between a gas molecule like CO and Pd nanoparticle.
The correlation suggested by van Noort1 in his Comment on our paper2 is an improvement of the Simamura correlation.3 Unfortunately, there is not sufficient information in our paper2 to compare both approaches. The uncertainties cited in ref 2 are not statistical but an expert’s estimation of the uncertainties of unknown melting points. The average deviations of experimental and estimated values from our correlation are 10 K for 61 chlorine-substituted dioxins (PCDDs) and 15 K for 59 chlorine-substituted dibenzofurans (PCDFs). The corresponding graphs are presented as Figures 1 and 2. So, our correlation is considerably better for PCDDs and the same for PCDFs. Literature Cited