Abstract
It was investigated how the modification of Ce1-xZrxO2-delta with alumina as structural additive affected the surface characteristics of the support. The effect of alkaline promoters on the catalyst coking resistance and activity was studied. Sorption-hydrolytic deposition technique was used to prepare a set of catalysts containing 1 wt.% Rh deposited on Al2O3.Ce0.75Zr0.25O2-delta, Ce0.75Zr0.25O2.delta and Al2O3-Ce0.75Zr0.25O2-delta, doped with alkaline metal. The catalysts were characterized by BET, TEM, SEM, XRD, TPO, and CO chemisorption methods. It was proved that the catalysts contained high-dispersion Rh particles of size 1-2 nm. The presence of Al deteriorated catalytic activity of Rh/ Al2O3-Ce0.75Zr0.25O2.delta for steam reforming of diesel surrogate (n-hexadecane) at T = 550 degrees C, H2O/C = 3.0, GHSV = 20,000 h-1, whereas the alkaline additives promoted n-hexadecane steam reforming. rth/Ce0.75Zr0.25O2-delta appeared to be the most stable catalyst, as it provided 100% conversion of n-hexadecane during 15 h on stream. The active component Rh/Ce0.75Zr0.25O2-delta was supported on FeCrAl alloy wire mesh using alumina as a binding structural component. The obtained catalyst Rh/Ce0.75Zr0.25O2-delta-Al2O3/FeCrAl was tested in the autothermal reforming of n-hexadecane at various temperatures and gas flow rates. Operating conditions were found to provide a 100% conversion of n-hexadecane and stable catalyst activity.