Yes, ‘Such As’ is widely accepted as a formal phrase that can be used in formal writing. The phrase ‘Such As’ is mainly used for the example of ‘Noun’ or the subject that coming in the main clause of the sentence. Here is a sentence that uses ‘Such As’ to mention some examples: ‘In this zoo, there are many endangered animals, such as Amur Leopards, Gorillas, and Sea Turtles’.