Can I purchase the VTC equipment with FY21 funds, then purchase the installation of the new VTC equipment with FY22 funds?
I don't see your proposed action as "splitting requirements" in the traditional, prohibited sense. The FAR doesn't specifically define “splitting requirements” but it's generally considered to be breaking a requirement into two or more purchases to avoid regulatory and/or approval mandates associated with a higher dollar threshold. FAR 13.003(c)(2) states: "Do not break down requirements aggregating more than the simplified acquisition threshold (or for commercial items, the threshold in Subpart 13.5) or the micro-purchase threshold into several purchases that are less than the applicable threshold merely to— (i) Permit use of simplified acquisition procedures; or (ii) Avoid any requirement that applies to purchases exceeding the micro-purchase threshold." Splitting requirements usually occurs to keep actions under the micropurchase or simplified acquisition thresholds. However, that is not the intent in your case.