에틸렌을 중합하기 위하여 시리카에 담지된 크롬촉매를 혼합법, 함침법 및 공침전법으로 제조하여 촉매활성을 조사하였다.
혼합법으로 제조된 촉매는 촉매활성을 전연 나타내지 않았으나, 함침법과 공침전법으로 제조된 촉매는 높은 촉매활성을 나타내었으며, 600 ℃에서 1시간 진공하였을 때 최대활성을 나타내었다.
에틸렌 중합의 촉매활성점은 촉매가 CO로 환원되는 시간에 따른 촉매활성의 변화, 환원된 촉매의 색깔의 변화 및 흡착된 NO종의 적외선 스펙트라에 의하여 Cr³⁺ 이온으로 밝혀졌다. 촉매는 Na 이온으로 피독되었으며 Na 이온의 농도가 20 ppm일 때 촉매활성을 완전히 잃었다.

The Chromium catalysts supported on silica for ethylene polymerization were prepared by mixing, impregnation, and coprecipitation methods and their caralytic activities were examined. As a consequence, it was found that both of co-precipitated and impregnated catalysts were very active, but mixed catalyst exhibited little catalytic activity. Co-precipitated and impregnated catalysts showed maximum polymerization activity under evacuation at 600 ℃ for 1 hr.
The active site responsible for ethylene polymerization was proved to be Cr³⁺ ion, as evidenced by the relationship between variation of catalytic activity and CO reduction time, the color change in reduced catalyst, and the infrared spectra of adsorbed nitric oxide. The catalyst was poisoned with sodium ion and its activity decreased with increase in the amount of sodium ion until 20 ppm.