近日，2022级硕士生崔力在植物资源辅助制备贵金属催化剂用于甘油氧化制备1,3-二羟基丙酮（DHA）领域取得新进展，相关研究成果以“Plant-mediated biosynthesized Au/CuO catalysts for efficient glycerol oxidation to 1,3-dihydroxyacetone: effect of biomass component on catalytic activity”为题，在线发表在《New Journal of Chemistry》期刊（New J. Chem., 2024,48, 19206-19219；IF= 2.76，JCR二区）。
甘油氧化制备1,3-二羟基丙酮（DHA）是一种兼具经济性与高效性的转化过程，DHA广泛应用于精细化工、医药和食品加工领域。然而，现有催化剂设计方法仍面临改进空间，尤其是在提高催化活性，选择性和生物相容性方面。课题组基于生物基催化剂开发的前期工作（Nanotechnology, 2023, 34, 365713）,在本研究中创新性地提出以植物提取物分离组份调控催化剂性能。通过从丁香叶（Syringa oblata Lindl.）中分离活性组分，并结合柱层析技术有效筛选植物成分，成功制备了一系列Au/CuO催化剂（如Scheme 1所示）。研究发现，富含酚类物质的组分（S3）制备的Au/CuO催化剂表现出最佳催化性能，其在100°C、1 MPa O2条件下甘油转化率达到86.6%，DHA选择性为82.0%。
Scheme 1. (a) Flow chart of Au/CuO preparation from isolated samples of SoL. (b) Schematic representation of glycerol catalytic oxidation reaction and detection.
实验表征显示，S3组分不仅具有优异的还原性，还能通过均匀分布的Au纳米颗粒增强催化剂的低温还原性。H2-TPR、XRD和TEM等表征证实，S3组分促进了Au和CuO的强相互作用，提高了活性位点的分布与利用效率。一系列实验与表征揭示了分离样品之间还原性和保护能力的差异，并系统地优化了获得最佳性能的制备和甘油反应条件。
本研究为利用植物资源制备绿色、可持续贵金属催化剂提供了新思路，并拓展了其在甘油转化领域的应用前景。此成果为开发高效催化剂设计方法提供了理论指导，也为可再生资源的高值化利用做出了重要贡献。
本研究工作得到了课题组刘海老师、袁振老师的悉心指导。
全文链接：https://doi.org/10.1039/D4NJ03594A
图文解析
通过傅里叶红外技术对柱层析法分离的产物进行分析，确定了以sloading 2，S3和S6为代表的三类紫丁香分离产物。
Figure 1. Infrared spectra of each isolate of SoL (a and b).
通过UV-Vis和TEM表征分析不同还原产物对Au NPs的还原性能和保护性能。
Figure 2. UV-Vis spectra of gold sols prepared from separated samples at different concentrations (a) Sloading 2, 0.1 mg/ml, (b) Sloading 2, 0.5 mg/ml, (c) Sloading 2, 2.0 mg/ml, (d) Sloading 2, comparison of three concentrations reacted for 4 h, (e) S3, 0.1 mg/ml, (f) S3, 0.5 mg/ml, (g) S3, 2.0 mg/ml, (h) S3, a comparison of the three concentrations for a 4 h reaction, (i) S6, 0.1 mg/ml, (j) S6, 0.5 mg/ml, (k) S6, 2.0 mg/ml, (l) S6, a comparison of the three concentrations for a 4 h reaction.
Figure 3. (a) UV-Vis spectral analysis of Au NPs prepared from different isolation products for 4 h. TEM images and particle size statistics of Au NPs prepared from different isolation products: (b) Sloading1, (c) Sloading2, (d) S0, (e) S1, (f) S2, (g) S3, (h) S4, (i) S5, (j) S6, (k) S7, (l) S8.
对不同分离产物进行制备Au/CuO，并且进行晶形，比表面积和孔道结构分析，并且进行甘油仲羟基催化氧化实验，并将性能最佳的S3-Au/CuO和近几年Au基催化剂甘油仲羟基催化性能进行对比，并结合表征进行分析。
Figure 4. (a) XRD analysis, (b) nitrogen adsorption/desorption isotherms, and (c) pore size distributions of isolated product-Au/CuO catalysts.
Figure 5 (a) Data on the catalytic oxidation of glycerol with different isolates and carriers, (b) Comparison of the performance of S3-Au/CuO catalyst with other Au-based catalysts.
Figure 6. (a) TG plot of isolated product S3, (b) H2-TPR analysis of catalysts and support.
对催化剂的制备条件和反应条件进行系统优化，并结合表征进行证明。
Figure 7. (a) XRD analysis of Au/CuO catalysts prepared with different S3 concentrations. TEM spectra and particle size statistics of Au/CuO catalysts prepared with varying concentrations of S3: (b) 0.2 mg/mL, (c) 0.5 mg/mL, (d) 1 mg/mL, (e) 2 mg/mL, (f) 4 mg/mL. (g) TEM-mapping of 2 mg/mL-S3-Au/CuO catalysts. (The red-marked circles in the TEM analysis images indicate the Au nanoparticles used for particle size statistics, while the larger mass, approximately 20 nm in size, represents the CuO support.)
Figure 8. The plot of catalytic oxidation data of glycerol catalyzed by isolated samples Sloading2, S3, and S6 prepared at different concentrations of Au/CuO catalysts. Reaction condition: GLY/Au=100/1 (mol/mol), 100°C，1 MPa O2，500 rpm，2 h.
Figure 9. The regulation of the S3-Au/CuO catalyst under varying preparation conditions, including (a) calcination temperature, (b) surface Au loading, and different reaction conditions, such as (c) reaction temperature and (d) reaction time.