Catholics agree that salvation is of grace alone.
We do not believe in faith alone because it is refuted in Scripture.
You have yet to demonstrate the genuine faith alone is all that is required for salvation. You claim that faith alone is refuted by scripture but haven’t backed up your statement. Are you claiming that James 2 refutes faith alone?? As has been pointed out - James is merely saying that genuine faith, and not a superficial faith, is needed in order to receive God’s grace.
Scripture is clear that salvation is a gift that can’t be earned. Noone can boast about earning salvation by the things that they do, only by receiving the grace of God and being born again can one enter the Kingdom of God.