Highlight the Emoji image you want to use and copy it. Paste it into your title.
Note 1: Don't copy and paste the code (example: 🚀) but rather the actual image (example: 🚀). You can use the code in the main text area, but not the title. The actual image can be used in both.
Note 2: You can go to the SteemIt Emojis Master List to see a full list of emojis.