Fig. 2

Yield—a 3D surface plot, b 2D contour plot KOH vs. temperature—data analysis was performed by Design Expert (Version 13)—https://www.statease.com/software/design-expert.

Yield—a 3D surface plot, b 2D contour plot KOH vs. temperature—data analysis was performed by Design Expert (Version 13)—https://www.statease.com/software/design-expert.