Arnold's research has led to the development of numerous biocatalytic processes that utilize enzymes as catalysts to perform chemical reactions. These processes offer several advantages over traditional chemical methods, including lower energy consumption, reduced waste generation, and the use of renewable resources.

Arnold's lab has engineered enzymes to improve the efficiency of biofuel production from renewable feedstocks. This work contributes to the development of sustainable and alternative energy sources.

Arnold's work has also led to the development of enzymes for the synthesis of pharmaceuticals. This has enabled the production of drugs in a more environmentally friendly and cost-effective manner.

Arnold is a strong advocate for green chemistry principles and promotes the adoption of sustainable technologies in the chemical industry. She actively encourages researchers and companies to consider the environmental impact of their processes and to seek more sustainable alternatives.