Catalytic fast pyrolysis of cellulose for selective production of 1-hydroxy-3,6-dioxabicyclo[3.2.1]octan-2-one using nickel-tin layered double oxides

Abstract

As a value-added chiral chemical, 1-hydroxy-3,6-dioxobicyclo[3.2.1]oct-2-one (LAC) can be obtained via cellulose pyrolysis, but its yield is extremely low in the conventional pyrolysis process. Herein, novel nickel-tin layered double oxide (NiSn-LDO) catalysts were developed for the selective production of LAC from the in-situ catalytic fast pyrolysis (CFP) of cellulose. Several layered double oxides (LDOs) were prepared and evaluated via pyrolysis-chromatography/mass spectrometry (Py-GC/MS) tests for the in-situ CFP of cellulose. NiSn-LDO was determined as the most capable catalyst for selective LAC preparation, and further experiments were conducted to confirm the optimal condition to produce LAC over several essential factors of reaction temperature, Ni/Sn molar ratio in the NiSn-LDO catalyst, and catalyst-to-cellulose (CA-to-CL) ratio. The results demonstrated that LAC was sensitive to the reaction conditions, and its yield always exhibited the tide of first increasing followed with decreasing along with the increase of pyrolysis temperature, Ni/Sn molar ratio, and CA-to-CL ratio. The maximal LAC yield reached 9.11 wt% over the pyrolysis temperature of 320 °C using NiSn-LDO with a Ni/Sn molar ratio of 2/1 at the CA-to-CL ratio of 1/1, which was more than 5 times of that from the non-catalytic process (1.72 wt%). In addition, the NiSn-LDOs possessed much better catalytic capability to yield LAC with high selectivity than previously reported catalysts.