iphone11 does not support qc fast charge, because the QC fast charge protocol is used by the Qualcomm system, generally using the Qualcomm CPU will support the fast charge protocol, and Apple's words are self-developed CPU, so they are using the pd charging protocol, the charging head with the QC protocol can not give him fast charge. Of course, it is still possible to charge at a normal slow speed.
The iphone11 supports qc fast charging, with a maximum of 18 watts of charging power