**Conversion of Xylose to Furfural over Lignin-Based Activated Carbon-Supported Iron Catalysts**

#### **Annu Rusanen 1,\*, Riikka Kupila 2, Katja Lappalainen 1,2, Johanna Kärkkäinen 1, Tao Hu 1 and Ulla Lassi 1,2**


Received: 30 June 2020; Accepted: 20 July 2020; Published: 22 July 2020

**Abstract:** In this study, conversion of xylose to furfural was studied using lignin-based activated carbon-supported iron catalysts. First, three activated carbon supports were prepared from hydrolysis lignin with different activation methods. The supports were modified with different metal precursors and metal concentrations into five iron catalysts. The prepared catalysts were studied in furfural production from xylose using different reaction temperatures and times. The best results were achieved with a 4 wt% iron-containing catalyst, 5Fe-ACs, which produced a 57% furfural yield, 92% xylose conversion and 65% reaction selectivity at 170 ◦C in 3 h. The amount of Fe in 5Fe-ACs was only 3.6 μmol and using this amount of homogeneous FeCl3 as a catalyst, reduced the furfural yield, xylose conversion and selectivity. Good catalytic activity of 5Fe-ACs could be associated with iron oxide and hydroxyl groups on the catalyst surface. Based on the recycling experiments, the prepared catalyst needs some improvements to increase its stability but it is a feasible alternative to homogeneous FeCl3.

**Keywords:** furfural; carbon-supported catalyst; xylose conversion; iron; heterogeneous catalysts
