Abstract:

Structured anodic AlOOH with dominant facets has catalytic characteristics of formaldehyde at low temperature, which were developed and investigated in terms of the catalytic performance in formaldehyde oxidation. To enrich the surface hydroxyl content of AlOOH, Pt/Na_x/AlOOH catalysts with different Na contents (0.13%, 0.19%, 0.30%, 0.41%) were prepared by Na₂CO₃ as Na precursor impregnation method. The results given by BET, FTIR and XPS indicate that the soidum-modified Na/AlOOH has much more surface hydroxyls groups, the specific surface area of Pt/Na_x/AlOOH and the catalysts have higher Pt dispersion and smaller Pt NPs. When Na content was 0.41%, the Pt dispersion of Pt/0.41Na/AlOOH reached to 56%. The results testified that HCHO was completely diminished at 60℃ over Pt/0.41Na/AlOOH, which has the highest catalytic activity of formaldehyde.

Key words: anodic alumina, HCHO decomposition, Na-modified, Pt dispersion, nanoparticle catalyst

摘要：

具有晶面取向的阳极氧化AlOOH因其低温甲醛催化性能而被用于催化氧化甲醛体系。为丰富AlOOH表面羟基含量，采用Na₂CO₃为Na前体浸渍法改性载体，制备不同Na含量（0.13%、0.19%、0.30%、0.41%，质量分数）的Pt/Na_x/AlOOH催化剂。通过BET、FTIR、XPS、HRTEM等表征分析，发现加入Na后，Na/AlOOH的表面羟基更加丰富，Pt/Na_x/AlOOH催化剂的比表面积增大，拥有更小的Pt颗粒尺寸，表面Pt颗粒分散度提高，Pt0元素价态含量增加。当Na含量为0.41%时，催化剂Pt/0.41Na/AlOOH的Pt分散度高达56%。实验结果证明，Pt/0.41Na/AlOOH展现出最优的HCHO催化活性，60℃时HCHO转化率达100%。

关键词: 阳极氧化铝, 甲醛分解, 金属钠, 铂分散度, 纳米结构催化剂