You can indeed become Catholic even though your wife is not interested in converting. Please be aware that you really have no choice. If you know that Catholic Christianity is true then in conscience you must convert because that it is God’s will for you.
You may or may not have smooth sailing with your wife should you join the Catholic Church. This, however, should not hold you back. Jesus tells us that if we put family or anything else ahead of him then we are not worthy of him.
There are things that you can do that will keep your marriage happy and whole. Always remember that you are going to be a Catholic husband and father. When you answer this call, you are answering the call of Jesus to live out your wedding vows in the same way that He is a spouse to His Church. Show your wife how your faith has transformed you as a husband. When she “sees” the transformation lived out in you as her husband, she will become interested in knowing more about being Catholic.
You can also get Catholic literature that will help you explain the Catholic faith and answer the many questions and doubts that she may have. Simply having such material in the house may create curiousity within her. Never preach at her or show any signs of negativity toward her or her beliefs. You have an incredible opportunity to lead your wife closer to God.
Do not be afraid…the situation with your wife is an opportunity rather than an obstacle. The enemy will try to thwart you in your journey to the Church and he will throw up every conceiveable road block. Pray and have faith…it may take many years but your wife will be sanctified by God through you.