Q: How to write an introduction for a literature review?

I assume that you are referring to a literature review as a standalone article and not the literature review that is part of the introduction of an original research paper.

If you are writing a standalone literature review article, the purpose of your introduction will be to establish the context of the field of research and the topic of the review. Thus, you can begin with a generic introduction that provides information about your field of study. You can then gradually narrow down to your topic, explain why you have chosen it and how and why it is relevant within the field. Finally, you can go a step further and explain what the focus of your literature review will be.

Related reading:

• A young researcher's guide to writing a literature review
• How to write a literature review
• 5 Tips to write a great literature review
• How to write a chronological literature review?