Similar catalytic systems, such as Pd/Al 2 O 3, were studied by the Freund group, wherein they measured lattice parameters as a function of particle size by TEM and reported a reduction of the distances within the lattice with decreasing cluster size.[ 40 ] Moreover, a recent study of γ-Al 2 O 3 -supported Pt particles with an average diameter of 1 nm demonstrated a Pt–Pt bond length contraction at elevated temperatures.[ 41 ] The largest rhodium particles were observed for zirconiated rhodium catalysts throughout CO exposure at the temperatures studied.