摘要
研究了MnOx/ZrO2 催化剂中添加的碱金属助剂对以合成气合成甲醇及异丁醇反应的影响 ,并采用BET ,XRD和NH3 TPD等表征技术 ,考察了碱金属助剂的添加对催化剂结构和表面性质的影响 .结果表明 ,碱金属助剂对MnOx/ZrO2 催化剂的催化性能有明显影响 .在实验条件下 ,添加 1 0 %K(K2 CO3作为前驱物 )的催化剂 ,其催化性能最好 ,醇的选择性高达 74 8% ,异丁醇选择性达 16 3 % .添加碱金属助剂也使MnOx/ZrO2 催化剂的表面性质发生了很大变化 。
The influence of alkali promoters on the catalytic performance of MnO_x/ZrO_2 for the selective synthesis of methanol and isobutanol from syngas was studied. The crystal structure, BET specific surface area and acidic properties of catalyst samples were measured by XRD, N_2 adsorption and NH_3-TPD. It was found that the addition of alkali promoters had an obvious influence on the performance of MnO_x/ZrO_2 catalyst. The selectivity for isobutanol increased in the order of Na<Li<Rb<Cs<K, which indicated that the moderately basic additives were desired for the formation of isobutanol on MnO_x/ZrO_2 catalyst. The selectivity for isobutanol was strongly dependent on the anions of the potassium salts, increasing in the order of OH -<C_2O 2-_4<NO -_3<CO 2-_3, which revealed that a moderate alkali promotion was required. The catalyst of 1%K/MnO_x/ZrO_2 (K_2CO_3 as precursor) showed higher activity and selectivity for isobutanol under the conditions of 10?000 h -1, 8.0 MPa and 673 K. The selectivity for alcohols and isobutanol was 74.8% and 16.3%, respectively. The results of characterization suggested that the acidic or basic property on the catalyst surface may play an important role in the formation of isobutanol.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2003年第2期111-114,共4页
基金
中国科学院创新基金资助课题 (KGCX2 30 2 0 1)
