Employer will match pension to 14% - should I increase contributions?

So I have an annual salary of £55k and change and currently contribute 6% to my pension which my employer matches. I found out they will match up to 14% which seems insane to me. I'm struggling to understand what I should do, so a bit of context.

I have a 3 year old, I own a house, I have a partner (not married but live together). Feel quite secure in the present moment, but I didn't start earning a pension until I was 23, so I only have 10ish years of pension in the pot, and only 5 of those were on a decent salary. I also have an undergraduate and postgraduate student loan to pay off, so at the moment I basically see about 72% of my income.

I think I will definitely increase my contributions, but don't know by how much. Can I increase my contributions so that my pre-tax salary is reduced below the 40% tax threshold? I understand that only the top 5k is taxed at 40%, but the idea that none of that 5k gets taxed and goes to my pension instead sounds quite appealing.