| Autor: |
Chen H; Laboratoire de Chimie des Processus Biologiques (LCPB), CNRS UMR 8229, Collège de France, PSL University, Sorbonne Université, Paris 75231, France., Brubach JB; Synchrotron SOLEIL, L'Orme des Merisiers, Départementale 128, Saint-Aubin 91190, France., Tran NH; Laboratoire de Chimie des Processus Biologiques (LCPB), CNRS UMR 8229, Collège de France, PSL University, Sorbonne Université, Paris 75231, France., Robinson AL; Laboratoire de Chimie des Processus Biologiques (LCPB), CNRS UMR 8229, Collège de France, PSL University, Sorbonne Université, Paris 75231, France.; Institut Lavoisier de Versailles, UVSQ, CNRS UMR 8180, Université Paris-Saclay, Versailles 78000, France., Romdhane FB; Fédération de Chimie et Matériaux de Paris-Centre (FCMat), 4 Place Jussieu, Paris 75005, France., Frégnaux M; Institut Lavoisier de Versailles, UVSQ, CNRS UMR 8180, Université Paris-Saclay, Versailles 78000, France., Penas-Hidalgo F; Laboratoire de Chimie des Processus Biologiques (LCPB), CNRS UMR 8229, Collège de France, PSL University, Sorbonne Université, Paris 75231, France., Solé-Daura A; Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo 1, Tarragona 43007, Spain., Mialane P; Institut Lavoisier de Versailles, UVSQ, CNRS UMR 8180, Université Paris-Saclay, Versailles 78000, France., Fontecave M; Laboratoire de Chimie des Processus Biologiques (LCPB), CNRS UMR 8229, Collège de France, PSL University, Sorbonne Université, Paris 75231, France., Dolbecq A; Institut Lavoisier de Versailles, UVSQ, CNRS UMR 8180, Université Paris-Saclay, Versailles 78000, France., Mellot-Draznieks C; Laboratoire de Chimie des Processus Biologiques (LCPB), CNRS UMR 8229, Collège de France, PSL University, Sorbonne Université, Paris 75231, France.; Institut Lavoisier de Versailles, UVSQ, CNRS UMR 8180, Université Paris-Saclay, Versailles 78000, France. |
| Abstrakt: |
We report the use of Zr-based metal-organic frameworks (MOFs) MOF-545 and MOF-545(Cu) as supports to prepare catalysts with uniformly and highly dispersed Ni nanoparticles (NPs) for CO 2 hydrogenation into CH 4 . In the first step, we studied the MOF support under catalytic conditions using operando diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, ex situ characterizations (PXRD, XPS, TEM, and EDX-element mapping), and DFT calculations. We showed that the high-temperature conditions undoubtedly confer a potential for catalytic functionality to the solids toward CH 4 production, while no role of the Cu could be evidenced. The MOF was shown to be transformed into a catalytically active material, amorphized but still structured with dehydroxylated Zr-oxoclusters, in line with DFT calculations. In the second step, Ni@MOF-545 catalysts were prepared using either impregnation (IM) or double solvent (DS) methods, followed by a dry reduction (R) route under H 2 to immobilize Ni NPs. The highest catalytic activity was obtained with the Ni@MOF-545 DS R catalyst (595 mmol CH4 g Ni -1 h -1 ) with 100% CH 4 selectivity and 60% CO 2 conversion after ∼3 h. The higher catalytic activity of Ni@MOF-545 DS R is a result of much smaller (∼5 nm) and better dispersed Ni NPs than in the IM sample (20-40 nm), the latter exhibiting sintering. The advantages of the encapsulation of Ni NPs by the DS method and of the use of a MOF-545-based support are discussed, highlighting the interest of designing yet-unexplored Zr-based MOFs loaded with Ni NPs for CO 2 hydrogenation. |
