Helmer Ryan, Borkar Siddhesh S, Li Aojie, Mahnaz Fatima, Vito Jenna, Iftakher Ashfaq, Hasan M M Faruque, Rangarajan Srinivas, Shetty Manish
Artie McFerrin Department of Chemical Engineering, Texas A&M University, 100 Spence Street, 77843, College Station, TX, USA.
Chemical and Biomolecular Engineering, Lehigh University, HST Building, L136 124 E. Morton Street, 18015, Bethlehem, PA, USA.
Angew Chem Int Ed Engl. 2025 Jan 21;64(4):e202416384. doi: 10.1002/anie.202416384. Epub 2024 Nov 7.
We demonstrate a novel approach of utilizing methanol (CHOH) in a dual role for (1) the methanolysis of polyethylene terephthalate (PET) to form dimethyl terephthalate (DMT) at near-quantitative yields (97 %) and (2) serving as an in situ H source for the catalytic transfer hydrogenolysis (CTH) of DMT to p-xylene (PX, ~63 % at 240 °C and 16 h) on a reducible ZnZrO supported Cu catalyst (i.e., Cu/ZnZrO). Pre- and post-reaction surface and bulk characterization, along with density functional theory (DFT) computations, explicate the dual role of the metal-support interface of Cu/ZnZrO in activating both CHOH and DMT and facilitating a lower free-energy pathway for both CHOH dehydrogenation and DMT hydrogenolysis, compared to Cu supported on a redox-neutral SiO support. Loading studies and thermodynamic calculations showed that, under reaction conditions, CHOH in the gas phase, rather than in the liquid phase, is critical for CTH of DMT. Interestingly, the Cu/ZnZrO catalyst was also effective for the methanolysis and hydrogenolysis of C-C bonds (compared to C-O bonds for PET) of waste polycarbonate (PC), largely forming xylenol (38 %) and methyl isopropyl anisole (~42 %) demonstrating the versatility of this approach toward valorizing a wide range of condensation polymers.
我们展示了一种利用甲醇（CH₃OH）的新方法，甲醇具有双重作用：（1）对聚对苯二甲酸乙二酯（PET）进行甲醇解，以接近定量的产率（约97%）生成对苯二甲酸二甲酯（DMT）；（2）作为原位氢源，用于在可还原的ZnZrO负载的Cu催化剂（即Cu/ZnZrO）上，将DMT催化转移氢解为对二甲苯（PX，在240℃和16小时时约为63%）。反应前后的表面和体相表征以及密度泛函理论（DFT）计算表明，与负载在氧化还原中性SiO载体上的Cu相比，Cu/ZnZrO的金属-载体界面在活化CH₃OH和DMT以及促进CH₃OH脱氢和DMT氢解的更低自由能途径方面具有双重作用。负载研究和热力学计算表明，在反应条件下，气相中的CH₃OH而非液相中的CH₃OH对于DMT的催化转移氢解至关重要。有趣的是，Cu/ZnZrO催化剂对废聚碳酸酯（PC）的C-C键（与PET的C-O键相比）的甲醇解和氢解也有效，主要生成二甲苯酚（约38%）和甲基异丙基苯甲醚（约42%），这表明该方法在将多种缩聚物增值方面具有通用性。
