Should a priest refuse to Baptize a baby for a serious reason, such as parents not willing to raise it in the Catholic Faith ?
Can. 868 §1. For an infant to be baptized licitly:
2/ there must be a founded hope that the infant will be brought up in the Catholic religion; if such hope is altogether lacking, the baptism is to be delayed according to the prescripts of particular law after the parents have been advised about the reason.
If the parents are unwilling to raise the child as a Catholic then I fail to see how the baptism can take place. The canon uses the word “delay” since the priest should use the opportunity not to simply refuse the baptism but to help the parents better understand the faith and hopefully enter more fully into living it.
CDF’s Pastoralis actio:
Assurances must be given that the gift thus granted can grow by an authentic education in the faith and Christian life, in order to fulfill the true meaning of the sacrament. As a rule, these assurances are to be given by the parents or close relatives, although various substitutions are possible within the Christian community. But if these assurances are not really serious there can be grounds for delaying the sacrament; and if they are certainly non-existent the sacrament should even be refused.
…In the first place it must be clear that the refusal of Baptism is not a means of exercising pressure. Nor can one speak of refusal, still less of discrimination, but rather of educational delay, according to individual cases, aimed at helping the family to grow in faith or to become more aware of its responsibilities.