Properties of Copper Catalysts Prepared by the Atomic Layer Epitaxy Technique

Atomic layer epitaxy (ALE) is a method for growing single crystals and thin films with the primary advantage that it allows a good conformal coating to obtain nano-particle of metals. This self-controlling feature of ALE allows the growth of uniform compound layers not only on flat substrates but on porous, heterogeneous surfaces. The ALE technique will be applied to produce uniform and high dispersion catalysts in this study. Recently, we have produced ca. 2-3 nm Cu particle on SiO2 support. The ALE-Cu/SiO2 catalyst with high dispersion and nano-scale Cu particle appears very different catalytic properties from the typical Cu based catalysts, which has satisfactorily thermal stability to resist the sintering of Cu particles at 773 K. Due to the small Cu particles formation, the ALE-Cu/SiO2 can strongly bind CO and give highly catalytic activity for CO2 converted to CO in reverse water gas shift reaction. The catalytic activity decreases in the order of 2.4% ALE-Cu/SiO2≒2 % Pt/SiO2＞2 % Pd/SiO2＞＞10.3 % IM-Cu/SiO2. In the first year, the fundamental properties of ALE Cu catalysts will be studied in that Cu precursor binding with porous support, decomposition of Cu precursor on support and formation mechanism of Cu particle from Cu precursor. In the second year, the studies will focus on the adsorption and desorption behavior of some chemical molecules on ALE Cu surface, such as CO, CO2, H2 and CH3OH. We will build up a flow reaction system combining FT-IR, TPD and GC-TCD techniques. Reaction mechanism will also be studied by using TPD-MASS and DRIFT experiments. In the third year, the ALE Cu catalysts will be investigated the aggregation of Cu particles under high temperature. We will focus the study on the fundamentally growth of Cu particles on surface. The examination of catalysts, by TPR, XRD, AES, ESCA etc., may be associated with experimental results of TPD and IR.

Project ID:PA9706-0690
External Project ID:NSC96-2113-M182-002-MY2