From haemoglobin to single-site hydrogenation catalyst. Issue 19 (9th September 2022)

• Record Type: Journal Article
• Authors: Li, Alain Y.; Pedersen, Angus; Feng, Jingyu; Luo, Hui; Barrio, Jesús; Roman, Julien; Hii, King Kuok (Mimi); Titirici, Maria-Magdalena
• Is Part Of: Green chemistry. Volume 24:Issue 19(2022)
• Page Start: 7574
• Page End: 7583
• Publication Date: 2022-09-09
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/d2gc02344j
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : A single-site Fe catalyst was prepared from bio-based precursors: xylose and haemoglobin. Its catalytic activity, selectivity, and recyclability for nitroarene transfer hydrogenation using isopropanol, and benzimidazole preparation, is reported. Abstract : Iron-based single-site catalysts hold immense potential for achieving highly selective chemical processes, with the added advantage of iron being an earth-abundant metal. They are widely explored in electrocatalysis for oxygen reduction and display promising catalytic activity for organic transformations. In particular, FeN x @C catalysts are active for the reduction of nitroarene into aromatic amines. Yet, they are difficult to mass-produce, and most preparation methods fail to avoid single site aggregation. Here we prepared FeN x @C catalysts from bio-derived compounds, xylose and haemoglobin, in a simple two-step process. Since haemoglobin naturally contains FeN x single-sites, we successfully repurposed them into hydrogenation catalytic centers and avoided their aggregation during the preparation of the material. Their single-site nature was demonstrated by aberration-corrected transmission electron microscopy and X-ray absorption techniques. They were shown to be active for transfer hydrogenation of nitroarenes into anilines, with excellent substrate selectivity and recyclability, as demonstrated by the preserved yield across seven catalytic cycles. We also showed that FeN x @C could be used to prepare 2-phenylbenzimidazole through a reduction/condensation tandem. Our work shows for the first time the viability of biomass precursors to prepare Fe single-site hydrogenation catalysts.