Described herein is a method of converting a first alcohol to a second alcohol that includes forming a mixture including a superparamagnetic catalyst and a feedstock, wherein the feedstock includes the first alcohol, and exposing the mixture to a fluctuating magnetic field to form a product, wherein the product includes a second alcohol having a longer carbon chain length than the first alcohol. A flow-through method is described for converting a first alcohol to a second alcohol, wherein the second alcohol has a longer carbon chain length than the first alcohol. Also described is a method of converting glycerol to butanol that includes forming a mixture including a superparamagnetic catalyst and a feedstock, wherein the feedstock includes glycerol, and exposing the mixture to a fluctuating magnetic field to form a product, wherein the product includes butanol. A flow-through method is described for converting glycerol to butanol.