Laminaria digitata and palmaria palmata seaweeds as natural source of catalysts for the cycloaddition of CO₂ to Epoxides

TY - JOUR

T1 - Laminaria digitata and palmaria palmata seaweeds as natural source of catalysts for the cycloaddition of CO2 to Epoxides

AU - Comerford, James William

AU - Gray, Thomas

AU - Lie, Yann

AU - MacQuarrie, Duncan James

AU - North, Michael

AU - Pellis, Alessandro

N1 - © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2019/1/12

Y1 - 2019/1/12

N2 - Seaweed powder has been found to act as an effective catalyst for the fixation of CO2 into epoxides to generate cyclic carbonates under solvent free conditions. Model background reactions were performed using metal halides and amino acids typically found in common seaweeds which showed potassium iodide (KI) to be the most active. The efficacy of the seaweed catalysts kelp (Laminaria digitata) and dulse (Palmaria palmata) was probed based on particle size, showing that kelp possessed greater catalytic ability, achieving a maximum conversion and selectivity of 63.7% to styrene carbonate using a kelp loading of 80% by weight with respect to epoxide, 40 bar of CO2, 120◦C for 3 h. Maximizing selectivity was difficult due to the generation of diol side product from residual H2O found in kelp, along with a chlorinated by-product thought to form due to a high quantity of chloride salts in the seaweeds. Data showed there was loss of organic matter upon use of the kelp catalyst, likely due to the breakdown of organic compounds and their subsequent removal during product extraction. This was highlighted as the likely cause of loss of catalytic activity upon reuse of the Kelp catalyst.

AB - Seaweed powder has been found to act as an effective catalyst for the fixation of CO2 into epoxides to generate cyclic carbonates under solvent free conditions. Model background reactions were performed using metal halides and amino acids typically found in common seaweeds which showed potassium iodide (KI) to be the most active. The efficacy of the seaweed catalysts kelp (Laminaria digitata) and dulse (Palmaria palmata) was probed based on particle size, showing that kelp possessed greater catalytic ability, achieving a maximum conversion and selectivity of 63.7% to styrene carbonate using a kelp loading of 80% by weight with respect to epoxide, 40 bar of CO2, 120◦C for 3 h. Maximizing selectivity was difficult due to the generation of diol side product from residual H2O found in kelp, along with a chlorinated by-product thought to form due to a high quantity of chloride salts in the seaweeds. Data showed there was loss of organic matter upon use of the kelp catalyst, likely due to the breakdown of organic compounds and their subsequent removal during product extraction. This was highlighted as the likely cause of loss of catalytic activity upon reuse of the Kelp catalyst.

KW - Clean synthesis

KW - CO sequestration

KW - Green catalyst

KW - Sustainability

UR - http://www.scopus.com/inward/record.url?scp=85059982256&partnerID=8YFLogxK

U2 - 10.3390/molecules24020269

DO - 10.3390/molecules24020269

M3 - Article

C2 - 30642040

AN - SCOPUS:85059982256

SN - 1420-3049

VL - 24

SP - 1

EP - 14

JO - MOLECULES

JF - MOLECULES

IS - 2

M1 - 269

ER -