The chemisorption and direct decomposition of NO on Rh（100） and Rh（111） surfaces were studied by the density functional theory（DFT） with Dmol3 program.The calculation results show that for the Rh（100）surface,the bridge sites are found to be the preferred adsorption site,but for the Rh（111） surface,the three fold hollow（hcp） sites are found to be the most stable one;the transition states were confirmed for the direct decomposition of NO on Rh（100） and Rh（111） surfaces by successful transition state search,and the activation energy are 161.91 kJ/mol for Rh（100） and 183.72 kJ/mol for Rh（111）,respectively.
