분말의 Zr(OH)_4를 (NH_4)2_CrO_4수용액에 함침시킨 후 공기중에 소성하여 질코니아에 담지된 산화크롬 촉매를 제조하였다. 제조된 CrO_x/ZrO_2 촉매상에 cumene을 반응시켜 산화-환원 거동을 연구한 결과 크롬의 산화상태가 +6인 chromate형태로 질코니아 표면에 존재할 때는 강한 산점이 생성되어 cumene의 탈알킬화 반응에 촉매활성을 나타내었다. 그러나 많은 양의 Cr^(6+)종은 반응중에 탈수소로 생성된 H_2에 의하여 환원되어 Cr^(3+)종으로 변화되었으며 Cr^(3+)종은 cumene을 탈수소화시켜 α-methyl styrene을 생성하는 반응에 활성점으로 작용하였다. 환원된 Cr^(3+)종은 0_2로 처리하면 다시 Cr^(6+)종으로 되고 따라서 산화된 촉매는 cumene의 탈알킬화 반응에 활성을 나타내었다.

Chromium oxide/zirconia catalysts were prepared by dry impregnation of Zr(OH)_4 powder with aqueous solution of (NH_4)_2CrO_4 followed by calcining in air. The redox behavior of prepared catalysts were investigated by reacting cumene as test material over catalysts. As a result it was found that Cr^(6+) species(as chromate) on the surface of catalyst was responsible for the formation of strong acid site and the catalytic activity for the dealkylation of cumene. However, much of the Cr^(6+) species was reduced to Cr^(3+) species by H_2 formed during the catalytic reaction of cumene and the reduced Cr^(3+) species was an active site for dehydrogenation of cumene to form α-methyl styrene. The reduced Cr^(3+) species was also reoxidized to a Cr^(6+) species after treatment with O_2 and consequently the reoxidized catalyst exhibited catalytic activity for the dealkylation reaction of cumene.