Carbon Nitride-Based Nanomaterials as a Sustainable Catalyst for Biodiesel Production

In this work, we investigated a seriesof carbon nitride-basednanomaterials (CNs), i.e., H-PHI, mpg-C3N4,PCN, Na-PHI, Mg-PHI, CN-OA-m, and LiK-PHI, as candidate catalystsfor biodiesel synthesis. The heterogeneous catalyst design based onCNs, with tunable catalytic sites and inexpensive syntheses, can allowbiodiesel production to become a more sustainable process, helpingto meet future energy demands. Transesterification of canola oil withmethanol using LiK-PHI as a catalyst, under the optimized conditions,displayed the best performance for biodiesel production with 94% ofyield and catalyst loading of 1.6 wt %. The outstanding performanceexhibitedby LiK-PHI is owed to this sample presenting the highest concentrationsof basic sites, among the CN materials tested, directly correlatedwith the alkali metal content. This is an important information tounderstand the very nature of these basic active sites, which wereexploited in this work to boost the catalyst efficiency among thebest in the field. Moreover, the biodiesel produced under the bestconditions, using LiK-PHI, was verified in relation to the numberof esters and glycerides in this product. All values are within thevalues previously established by legislation, 97.6% +/- 0.1 and0.20%, respectively, which indicates the high quality of biodieselproduced.

Automated summary

In this study, a series of carbon nitride-based nanomaterials were investigated as catalysts for biodiesel synthesis. LiK-PHI showed the best performance with a yield of 94% and catalyst loading of 1.6wt%. The biodiesel produced using LiK-PHI also met the quality requirements established by legislation.