Porous silica nano-flowers stabilized Pt–Pd bimetallic nanoparticles as heterogeneous catalyst for efficiently synthesizing guaiacol from 2-methoxycyclohexanol

• Published in: Chinese journal of chemical engineering Vol. 70; no. 6; pp. 222 - 233
• Main Authors: Feng, Junbo, Wu, Junyan, Yan, Dongdong, Zhang, Yadong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2024; School of Materials and Chemical Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China%School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China; State Key Laboratory of Coking Coal Exploitation and Comprehensive Utilization, Pingdingshan 467000, China; Jiyuan Research Institute, Zhengzhou University, Jiyuan 459000, China%School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China; School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China
• Subjects: 2-Methoxycyclohexanol; Dehydrogenation; Guaiacol; Nanoparticles; Supported catalyst; Nanoparticles; Guaiacol; Dehydrogenation; Supported catalyst; 2-Methoxycyclohexanol
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/j.cjche.2024.03.014

Porous silica nano-flowers (KCC-1) immobilized Pt–Pd alloy NPs (Pt–Pd/KCC-1) with different mass ratios of Pd and Pt were successfully prepared by a facile in situ one-step reduction, using hydrazinium hydroxide as a reducing agent. The as-synthesized silica nanospheres possess radial fibers with a distance of 15 nm, exhibiting a high specific surface area (443.56 m2·g−1). Meanwhile, the obtained Pt–Pd alloy NPs are uniformly dispersed on the silica surface with a metallic particle size of 4–6 nm, which exist as metallic Pd and Pt on the surface of monodisperse KCC-1, showing the transfer of electrons from Pd to Pt. The as-synthesized 2.5%Pt-2.5%Pd/KCC-1 exhibited excellent catalytic activity and stability for the continuous dehydrogenation of 2-methoxycyclohexanol to prepare guaiacol. Compared with Pt or Pd single metal supported catalysts, the obtained 2.5%Pt-2.5%Pd/KCC-1 shows 97.2% conversion rate of 2-methoxycyclohexanol and 76.8% selectivity for guaiacol, which attributed to the significant synergistic effect of bimetallic Pt–Pd alloy NPs. Furthermore, turn over frequency value of the obtained 2.5%Pt-2.5%Pd/KCC-1 NPs achieved 4.36 s−1, showing higher catalytic efficiency than other two monometallic catalysts. Reaction pathways of dehydro-aromatization of 2-methoxycyclohexanol over the obtained catalyst are proposed. Consequently, the obtained 2.5%Pt-2.5%Pd/KCC-1 NPs prove their potential in the dehydrogenation of 2-methoxycyclohexanol, while the kinetics and mechanistic study of the dehydrogenation reaction over the catalyst in a continuous fixed-bed reactor may provide valuable information for the development of green, outstanding and powerful synthetic pathway of guaiacol. [Display omitted] •Porous silica nano-flowers immobilized Pt–Pd alloy NPs (Pt–Pd/KCC-1) were prepared by a facile in situ one-step reduction.•The synthesized silica nanospheres possess radial fibers with a distance of 15 nm.•The 2.5%Pt-2.5%Pd/KCC-1 NPs exhibited high activity for dehydrogenation of 2-methoxycyclohexanol to prepare guaiacol.•Turn over frequency value of 2.5%Pt-2.5%Pd/KCC-1 NPs achieved 4.36 s-1, showing higher catalytic efficiency than Pt or Pd.